Rice Bowman–Birk inhibitor was expressed and crystallized.
Bowman–Birk inhibitors (BBIs) are cysteine-rich proteins with inhibitory activity against proteases that are widely distributed in monocot and dicot species. The expression of rice BBI from Oryza sativa is up-regulated and induced by pathogens or insects during germination of rice seeds. The rice BBI (RBTI) of molecular weight 15 kDa has been crystallized using the hanging-drop vapour-diffusion method. According to the diffraction of rice BBI crystals at a resolution of 2.07 Å, the unit cell belongs to space group P212121, with unit-cell parameters a = 74.37, b = 96.69, c = 100.36 Å. Preliminary analysis indicates four BBI molecules in an asymmetric unit, with a solvent content of 58.29%.
Bowman–Birk inhibitors; rice
Rice lectin was crystallized and analyzed by X-ray crystallography.
Lectins with sugar-binding specificity are widely distributed in higher plants and various other species. The expression of rice lectin from Oryza sativa is up-regulated in the growing coleoptile when anaerobic stress persists. A rice lectin of molecular weight 15.2 kDa has been crystallized using the hanging-drop vapour-diffusion method. From the diffraction of the lectin crystals at 1.93 Å resolution, the unit cell belongs to space group P31, with unit-cell parameters a = 98.58, b = 98.58, c = 44.72 Å. Preliminary analysis indicates that there are two lectin molecules in an asymmetric unit with a large solvent content, 70.1%.
XometC, a cystathionine γ-lyase-like protein from X. oryzae pv. oryzae and an antibacterial drug-target protein against bacterial blight, was cloned, purified and crystallized. Preliminary X-ray crystallographic analysis of XometC crystals was carried out.
Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight of rice (Oryza sativa L.), one of the most devastating diseases of rice in most rice-growing countries. XometC, a cystathionine γ-lyase (CGL) like protein that is an antibacterial drug-target protein against Xoo, was cloned, expressed, purified and crystallized. CGL catalyzes the second step in the reverse-transsulfuration pathway, which is essential for the metabolic interconversion of the sulfur-containing amino acids cysteine and methionine. Crystals of two different shapes, plate-shaped and pyramid-shaped, diffracted to 2.9 and 3.2 Å resolution and belonged to the primitive orthogonal space group P212121 and the tetragonal space group P41 (or P43), with unit-cell parameters a = 73.0, b = 144.9, c = 152.3 Å and a = b = 78.2, c = 300.7 Å, respectively. For the P212121 crystals, three or four monomers exist in the asymmetric unit with a corresponding V
M of 3.02 or 2.26 Å3 Da−1 and a solvent content of 59.3 or 45.7%. For the P41 (or P43) crystals, four or five monomers exist in the asymmetric unit with a corresponding V
M of 2.59 or 2.09 Å3 Da−1 and a solvent content of 52.5 or 40.6%.
bacterial blight; cystathionine γ-lyase; reverse transsulfuration pathway; Xanthomonas oryzae pv. oryzae
Crystallization of and preliminary crystallographic studies on an active-site mutant of pro-Tk-subtilisin from the hyperthermophilic archaeon T. kodakaraensis were performed.
Crystallization of and preliminary crystallographic studies on an active-site mutant of pro-Tk-subtilisin from the hyperthermophilic archaeon Thermococcus kodakaraensis were performed. The crystal was grown at 277 K by the sitting-drop vapour-diffusion method. Native X-ray diffraction data were collected to 2.3 Å resolution using synchrotron radiation from station BL41XU at SPring-8. The crystal belongs to the orthorhombic space group I222, with unit-cell parameters a = 92.69, b = 121.78, c = 77.53 Å. Assuming the presence of one molecule per asymmetric unit, the Matthews coefficient V
M was calculated to be 2.6 Å3 Da−1 and the solvent content was 53.1%.
pro-Tk-subtilisin; Thermococcus kodakaraensis
Rice BGlu1 β-glucosidase was purified from recombinant E. coli and crystallized with and without the inhibitor 2-deoxy-2-fluoro-β-d-glucose. The crystals diffracted to 2.15 and 2.75 Å, respectively.
Rice (Oryza sativa) BGlu1 β-glucosidase was expressed in Escherichia coli with N-terminal thioredoxin and hexahistidine tags and purified by immobilized metal-affinity chromatography (IMAC). After removal of the N-terminal tags, cation-exchange and S-200 gel-filtration chromatography yielded a 50 kDa BGlu1 with >95% purity. The free enzyme and a complex with 2,4-dinitrophenyl-2-deoxy-2-fluoro-β-d-glucopyranoside inhibitor were crystallized by microbatch and hanging-drop vapour diffusion. Small tetragonal crystals of BGlu1 with and without inhibitor grew in 18%(w/v) PEG 8000 with 0.1 M sodium cacodylate pH 6.5 and 0.2 M zinc acetate. Crystals of BGlu1 with inhibitor were streak-seeded into 23%(w/v) PEG MME 5000, 0.2 M ammonium sulfate, 0.1 M MES pH 6.7 to yield larger crystals. Crystals with and without inhibitor diffracted to 2.15 and 2.75 Å resolution, respectively, and had isomorphous orthorhombic unit cells belonging to space group P212121.
BGlu1 β-glucosidase; 2,4-dinitrophenyl-2-deoxy-2-fluoro-β-d-glucopyranoside; rice
The subtilisin-like serine protease carnein was isolated from the latex of the plant I. carnea, purified and crystallized by the hanging-drop vapour-diffusion method. A diffraction data set was collected to 2.0 Å resolution in-house from a single crystal at 110 K.
Carnein is an 80 kDa subtilisin-like serine protease from the latex of the plant Ipomoea carnea which displays an exceptional resistance to chemical and thermal denaturation. In order to obtain the first crystal structure of a plant subtilisin and to gain insight into the structural determinants underlying its remarkable stability, carnein was isolated from I. carnea latex, purified and crystallized by the hanging-drop vapour-diffusion method. A data set was collected to 2.0 Å resolution in-house from a single crystal at 110 K. The crystals belonged to the trigonal space group P3121 or P3221, with unit-cell parameters a = b = 126.9, c = 84.6 Å, α = β = 90, γ = 120°. Assuming the presence of one molecule per asymmetric unit, the Matthews coefficient is 2.46 Å3 Da−1, corresponding to a solvent content of 50%. Structure determination of the enzyme is in progress.
carnein; serine proteases; subtilisin
Xoo0352, which encodes d-alanine-d-alanine ligase A (DdlA), from X. oryzae pv. oryzae was cloned, purified and crystallized. Preliminary X-ray crystallographic analysis of DdlA crystals was performed.
Xanthomonas oryzae pv. oryzae (Xoo) causes bacterial blight (BB), which is one of the most devastating diseases of rice in most rice-growing countries. d-Alanine-d-alanine ligase A (DdlA), coded by the Xoo0352 gene, was expressed, purified and crystallized. DdlA is an enzyme that is involved in d-alanine metabolism and the biosynthesis of an essential bacterial peptidoglycan precursor, in which it catalyzes the formation of d-alanyl-d-alanine from two d-alanines, and is thus an attractive antibacterial drug target against Xoo. The DdlA crystals diffracted to 2.3 Å resolution and belonged to the primitive tetragonal space group P43212, with unit-cell parameters a = b = 83.0, c = 97.6 Å. There is one molecule in the asymmetric unit, with a corresponding V
M of 1.88 Å3 Da−1 and a solvent content of 34.6%. The initial structure was determined by molecular replacement using d-alanine-d-alanine ligase from Staphylococcus aureus (PDB code 2i87) as a template model.
bacterial blight; d-alanine-d-alanine ligase; peptidoglycan biosynthesis; Xanthomonas oryzae pv. oryzae
N-Acetylglucosamine 1-phosphate uridyltransferase (GlmU) from M. tuberculosis H37Rv has been crystallized and preliminary X-ray crystallographic analysis has been performed. GlmU is a bi-domained bifunctional enzyme that is involved in the biosynthesis of UDP-N-acetylglucosamine, a precursor in peptidoglycan biosynthesis in M. tuberculosis.
The gene product of open reading frame Rv1018c from Mycobacterium tuberculosis is annotated as encoding a probable N-acetylglucosamine 1-phosphate uridylyltransferase (MtbGlmU), an enzyme that catalyzes the biosynthesis of UDP-N-acetylglucosamine, a precursor common to lipopolysaccharide and peptidoglycan biosynthesis. Following overexpression in Escherichia coli, the enzyme was purified and crystallized using the hanging-drop vapour-diffusion method. Native diffraction data were collected from crystals belonging to space group R32 and processed to a resolution of 2.2 Å.
Mycobacterium tuberculosis H37Rv; Rv1018c; N-acetylglucosamine 1-phosphate uridyltransferase; peptidoglycan metabolism; GlmU
Preliminary X-ray crystallographic study of a proline-specific aminopepitdase from Aneurinibacillus sp, strain AM-1 was carried out.
To elucidate the structure and molecular mechanism of a characteristic proline-specific aminopeptidase produced by the thermophile Aneurinibacillus sp. strain AM-1, its gene was cloned and the recombinant protein was overexpressed in Escherichia coli, purified and crystallized using the hanging-drop vapour-diffusion method. X-ray diffraction data were collected to 1.8 Å resolution from the recombinant aminopeptidase crystal. The crystals belong to the orthorhombic space group P21212, with unit-cell parameters a = 93.62, b = 68.20, c = 76.84 Å. A complete data set was also obtained from crystals of SeMet-substituted aminopeptidase. Data in the resolution range 20–2.1 Å from the MAD data set from the SeMet-substituted crystal were used for phase determination.
proline-specific aminopeptidase; Aneurinibacillus sp. strain AM-1; thermophiles
Crystals of betaine aldehyde dehydrogenase 2 from rice (O. sativa L.) belonged to a C-centred orthorhombic space group and diffraceted X-rays to 2.6 Å resolution.
Fragrant rice (Oryza sativa L.) betaine aldehyde dehydrogenase 2 (OsBADH2) is a key enzyme in the synthesis of fragrance aroma compounds. The extremely low activity of OsBADH2 in catalyzing the oxidation of acetaldehyde is believed to be crucial for the accumulation of the volatile compound 2-acetyl-1-pyrroline (2AP) in many scented plants, including fragrant rice. Recombinant fragrant rice OsBADH2 was expressed in Escherichia coli as an N-terminal hexahistidine fusion protein, purified using Ni Sepharose affinity chromatography and crystallized using the microbatch method. Initial crystals were obtained within 24 h using 0.1 M Tris pH 8.5 with 30%(w/v) PEG 4000 and 0.2 M magnesium chloride as the precipitating agent at 291 K. Crystal quality was improved when the enzyme was cocrystallized with NAD+. Improved crystals were grown in 0.1 M HEPES pH 7.4, 24%(w/v) PEG 4000 and 0.2 M ammonium chloride and diffracted to beyond 2.95 Å resolution after being cooled in a stream of N2 immediately prior to X-ray diffraction experiments. The crystals belonged to space group C2221, with unit-cell parameters a = 66.03, b = 183.94, c = 172.28 Å. An initial molecular-replacement solution has been obtained and refinement is in progress.
Oryza sativa L.; betaine aldehyde dehydrogenases; OsBADH2; fragrant rice
Disproportionating enzyme from potato was crystallized and preliminarily analyzed using X-ray diffraction.
Disproportionating enzyme (D-enzyme; EC 22.214.171.124) is a 59 kDa protein that belongs to the α-amylase family. D-enzyme catalyses intramolecular and intermolecular transglycosylation reactions of α-1,4 glucan. A crystal of the D-enzyme from potato was obtained by the hanging-drop vapour-diffusion method. Preliminary X-ray data showed that the crystal diffracts to 2.0 Å resolution and belongs to space group C2221, with unit-cell parameters a = 69.7, b = 120.3, c = 174.2 Å.
disproportionating enzyme; intramolecular and intermolecular transglycosylation reactions
Rice (Oryza sativa) flour and maize (Zea mays) meal substitution in wheat (Triticum aestivum) flour, from 0 to 100% each, for the production of bread was investigated. The proximate analysis, pasting properties, bread making qualities of raw materials and sensory evaluation of the bread samples were determined. The pasting temperature increased with increased percentage of rice flour and maize meal. But the other pasting characters decreased with the higher proportion of rice flour. The baking absorption was observed to increase with higher level of maize meal but it decreased when level of rice flour was increased. Loaf weight (g) decreased with progressive increase in the proportion of maize meal but increased when rice flour incorporation was increased. Loaf volume, loaf height and specific volume decreased for progressively higher level of maize meal and rice flour. The sensory evaluation revealed that 25% replacement of wheat flour was found to be more acceptable than control sample.
Maize meal; Pasting properties; Rice flour; Sensory quality; Wheat flour
This article describes the first successful crystallization of a membrane-bound [NiFe] hydrogenase isolated from a photosynthetic organism (A. vinosum). The crystals obtained produced diffraction patterns up to 2.5 Å resolution.
The membrane-bound [NiFe] hydrogenase is a unique metalloprotein that is able to catalyze the reversible oxidation of hydrogen to protons and electrons during a complex reaction cycle. The [NiFe] hydrogenase was isolated from the photosynthetic purple sulfur bacterium Allochromatium vinosum and its crystallization and preliminary X-ray analysis are reported. It was crystallized by the hanging-drop vapour-diffusion method using sodium citrate and imidazole as crystallization agents. The crystals belong to space group P21212, with unit-cell parameters a = 205.00, b = 217.42, c = 120.44 Å. X-ray diffraction data have been collected to 2.5 Å resolution.
[NiFe] hydrogenases; photosynthetic purple sulfur bacteria; Allochromatium vinosum
Bacterial blight is a destructive disease of rice that is caused by X. oryzae pv. oryzae (Xoo). Dehydroquinate synthase, which is the second enzyme of the shikimate pathway, was cloned from Xoo1243 (aroB), purified and crystallized in order to elucidate its three-dimensional structure.
The disease bacterial blight results in serious production losses of rice in Asian countries. The aroB gene encoding dehydroquinate synthase (DHQS), which is a potential antibiotic target, was identified from the plant-pathogenic bacterium Xanthomonas oryzae pv. oryzae (Xoo). DHQS plays an essential role in the synthesis of aromatic compounds in the shikimate pathway. The aroB gene (Xoo1243) was cloned from Xoo and the corresponding DHQS protein was subsequently overexpressed in Escherichia coli. The purified protein was crystallized using the hanging-drop vapour-diffusion method and yielded crystals that diffracted to 2.5 Å resolution. The crystals belonged to the tetragonal space group P43212, with unit-cell parameters a = b = 118.2, c = 98.2 Å. According to a Matthews coefficient calculation, the crystal contained two molecules in the asymmetric unit, with a corresponding V
M of 2.06 Å3 Da−1 and a solvent content of 40.4%.
aroB; bacterial blight; 3-dehydroquinate synthase; shikimate pathway; Xanthomonas oryzae pv. oryzae
The bifunctional enzyme catalase-phenol oxidase from S. thermophilum was crystallized by the hanging-drop vapour-diffusion method in space group P21 and diffraction data were collected to 2.8 Å resolution.
Catalase-phenol oxidase from Scytalidium thermophilum is a bifunctional enzyme: its major activity is the catalase-mediated decomposition of hydrogen peroxide, but it also catalyzes phenol oxidation. To understand the structural basis of this dual functionality, the enzyme, which has been shown to be a tetramer in solution, has been purified by anion-exchange and gel-filtration chromatography and has been crystallized using the hanging-drop vapour-diffusion technique. Streak-seeding was used to obtain larger crystals suitable for X-ray analysis. Diffraction data were collected to 2.8 Å resolution at the Daresbury Synchrotron Radiation Source. The crystals belonged to space group P21 and contained one tetramer per asymmetric unit.
Scytalidium thermophilum; Humicola insolens; catalases; phenol oxidases; catechol oxidases; CATPO
The crystallization and preliminary crystallographic studies of LipA, a lipase/esterase secreted by X. oryzae pv. oryzae during its infection of rice plants, are reported.
Xanthomonas oryzae pv. oryzae is the causal agent of bacterial leaf blight, a serious disease of rice. Several enzymes that are secreted through the type II secretion system of this bacterium play an important role in the plant–microbe interaction, being important for virulence and also being able to induce potent host defence responses. One of these enzymes is a secretory lipase/esterase, LipA, which shows a very weak homology to other bacterial lipases and gives a positive tributyrin plate assay. In this study, LipA was purified from the culture supernatant of an overexpressing clone of X. oryzae pv. oryzae and two types of crystals belonging to space group C2 but with two different unit-cell parameters were obtained using the hanging-drop vapour-diffusion method. Type I crystals diffract to a maximum resolution of 1.89 Å and have unit-cell parameters a = 93.1, b = 62.3, c = 66.1 Å, β = 90.8°. Type II crystals have unit-cell parameters a = 103.6, b = 54.6, c = 66.3 Å, β = 92.6° and diffract to 1.86 Å. Solvent-content analysis shows one monomer in the asymmetric unit in both the crystal forms.
secretory lipases; Xanthomonas oryzae pv. oryzae; plant pathogens
Repeat-associated small interfering RNAs (rasiRNAs) are derived from various genomic repetitive elements and ensure genomic stability by silencing endogenous transposable elements. Here we describe a novel subset of 46 rasiRNAs named LNCR rasiRNAs due to their homology with one long non-coding RNA (LNCR) of Spodoptera frugiperda. LNCR operates as the intermediate of an unclassified transposable element (TE-LNCR). TE-LNCR is a very invasive transposable element, present in high copy numbers in the S. frugiperda genome. LNCR rasiRNAs are single-stranded RNAs without a prominent nucleotide motif, which are organized in two distinct, strand-specific clusters. The expression of LNCR and LNCR rasiRNAs is developmentally regulated. Formation of heterochromatin in the genomic region where three copies of the TE-LNCR are embedded was followed by chromatin immunoprecipitation (ChIP) and we observed this chromatin undergo dynamic changes during development. In summary, increased LNCR expression in certain developmental stages is followed by the appearance of a variety of LNCR rasiRNAs which appears to correlate with subsequent accumulation of a heterochromatic histone mark and silencing of the genomic region with TE-LNCR. These results support the notion that a repeat-associated small interfering RNA pathway is linked to heterochromatin formation and/or maintenance during development to establish repression of the TE-LNCR transposable element. This study provides insights into the rasiRNA silencing pathway and its role in the formation of fluctuating heterochromatin during the development of one holocentric organism.
A thermostable ribonuclease HIII from B. stearothermophilus (Bst RNase HIII) was crystallized and preliminary crystallographic studies were performed. Plate-like overlapping polycrystals were grown by the sitting-drop vapour-diffusion method at 283 K.
A thermostable ribonuclease HIII from Bacillus stearothermophilus (Bst RNase HIII) was crystallized and preliminary crystallographic studies were performed. Plate-like overlapping polycrystals were grown by the sitting-drop vapour-diffusion method at 283 K. Native X-ray diffraction data were collected to 2.8 Å resolution using synchrotron radiation from station BL44XU at SPring-8. The crystals belong to the orthorhombic space group P21212, with unit-cell parameters a = 66.73, b = 108.62, c = 48.29 Å. Assuming one molecule per asymmetric unit, the V
M value was 2.59 Å3 Da−1 and the solvent content was 52.2%.
The purification, crystallization and preliminary X-ray crystallographic analysis of glyceraldehyde-3-phosphate dehydrogenase 1 (GAP1) from MRSA252 in the apo form is reported.
Glyceraldehyde-3-phosphate dehydrogenase 1 (GAP1) from methicillin-resistant Staphylococcus aureus (MRSA252) has been purified to homogeneity in the apo form. The protein was crystallized using the hanging-drop vapour-diffusion method. The crystals belonged to space group P21, with unit-cell parameters a = 69.95, b = 93.68, c = 89.05 Å, β = 106.84°. X-ray diffraction data have been collected and processed to a maximum resolution of 2.2 Å. The presence of one tetramer in the asymmetric unit gives a Matthews coefficient (V
M) of 1.81 Å3 Da−1 with a solvent content of 32%. The structure has been solved by molecular replacement and structure refinement is now in progress.
glyceraldehyde-3-phosphate dehydrogenase 1; Staphylococcus aureus; MRSA252
The cloning, expression, purification, crystallization and preliminary X-ray characterization of an l-N-carbamoylase from G. stearothermophilus are described.
N-Carbamoyl-l-amino-acid amidohydrolases (l-N-carbamoylases; EC 126.96.36.199) hydrolyze the carbon–nitrogen bond of the ureido group in N-carbamoyl-l-α-amino acids. These enzymes are commonly used in the production of optically pure natural and non-natural l-amino acids using the ‘hydantoinase process’. Recombinant l-N-carbamoylase from Geobacillus stearothermophilus CECT43 has been expressed, purified and crystallized by hanging-drop vapour diffusion. X-ray data were collected to a resolution of 2.75 Å. The crystals belonged to space group P21212, with unit-cell parameters a = 103.2, b = 211.7, c = 43.1 Å and two subunits in the asymmetric unit.
l-N-carbamoylases; N-carbamoyl-l-amino-acid amidohydrolases; hydantoinase process; peptidase family
The expression, purification, crystallization and preliminary X-ray diffraction analysis of CTP:inositol-1-phosphate cytidylyltransferase from A. fulgidus is described.
Archaeoglobus fulgidus, a hyperthermophilic archaeon, accumulates di-myo-inositol phosphate (DIP) in response to heat stress. Recently, the pathway for biosynthesis of DIP has been elucidated in this organism and involves a bifunctional enzyme that contains two domains: CTP:inositol-1-phosphate cytidylyltransferase (IPCT) as a soluble domain and di-myo-inositol-1,3′-phosphate-1-phosphate synthase (DIPPS) as a membrane domain. Here, the expression, purification, crystallization and preliminary X-ray diffraction analysis of the IPCT domain from A. fulgidus in the apo form are reported. The crystals diffracted to 2.4 Å resolution using a synchrotron source and belonged to the orthorhombic space group P21212, with unit-cell parameters a = 154.7, b = 83.9, c = 127.7 Å.
CTP:inositol-1-phosphate cytidylyltransferase; Archaeoglobus fulgidus; compatible solutes; CDP-inositol; di-myo-inositol phosphate
The crystallization and preliminary X-ray crystallographic analysis of a protease inhibitor from the haemolymph of the Indian tasar silk worm A. mylitta is reported.
A protein with inhibitory activity against fungal proteases was purified from the haemolymph of the Indian tasar silkworm Antheraea mylitta and was crystallized using the hanging-drop vapour-diffusion method. Polyethylene glycol 3350 was used as a precipitant. Crystals belonged to space group P6322, with unit-cell parameters a = b = 60.6, c = 85.1 Å. X-ray diffraction data were collected and processed to a maximum resolution of 2.1 Å.
protease inhibitors; haemolymph; Antheraea mylitta
Tthe cloning, expression, purification, crystallization and preliminary X-ray crystallographic analysis of a bifunctional purine-biosynthesis enzyme from E. coli which possesses aminoimidazole-4-carboxamide ribonucleotide transformylase and IMP cyclohydrolase activities are reported.
In bacteria and eukaryotes, the last two steps of de novo purine biosynthesis are catalyzed by bifunctional purine-biosynthesis protein (PurH), which is composed of two functionally independent domains linked by a flexible region. The N-terminal domain possesses IMP cyclohydrolase activity and the C-terminal domain possesses aminoimidazole-4-carboxamide ribonucleotide transformylase activity. This study reports the expression, purification, crystallization and preliminary X-ray crystallographic analysis of PurH from Escherichia coli with an N-terminal His6 tag. The crystals diffracted to a maximum resolution of 3.05 Å and belonged to the monoclinic space group P21, with unit-cell parameters a = 76.37, b = 132.15, c = 82.64 Å, β = 111.86°.
purine biosynthesis; PurH
The crystallization and preliminary X-ray crystallographic analysis of a 23 kDa GroEL1 fragment from M. tuberculosis H37Rv is reported.
Full-length GroEL1 from Mycobacterium tuberculosis H37Rv was cloned, overexpressed and purified. Crystals were obtained by the hanging-drop vapor-diffusion method and contained a 23 kDa GroEL1 fragment. A complete native data set was collected from a single frozen crystal that belonged to the orthorhombic space group P21212, with unit-cell parameters a = 75.47, b = 78.67, c = 34.89 Å, α = β = γ = 90°, and diffracted to 2.2 Å resolution on a home X-ray source.
Mycobacterium tuberculosis; chaperonins; GroEL1
Leucine aminopeptidase, an exopeptidase that hydrolyzes leucine from the N-terminus of polypeptides, from X. oryzae pv. oryzae was cloned, expressed and crystallized.
Xanthomonas oryzae pv. oryzae (Xoo) causes the serious disease bacterial blight in rice. The pepA (Xoo0834) gene from Xoo is one of around 100 genes that have been selected for the design of antibacterial drugs. The pepA gene encodes leucine aminopeptidase (LAP), an exopeptidase that catalyzes the hydrolysis of leucine residues from the N-terminus of a protein or peptide. This enzyme was expressed in Escherichia coli, purified and crystallized, and preliminary X-ray structural studies have been carried out. The LAP crystal diffracted to 2.6 Å resolution and belonged to the cubic space group P213. The unit-cell volume of the crystal was compatible with the presence of two monomers in the asymmetric unit.
Xanthomonas oryzae pv. oryzae; leucine aminopeptidase