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1.  A Novel Integrative Conjugative Element Mediates Genetic Transfer from Group G Streptococcus to Other β-Hemolytic Streptococci▿  
Journal of Bacteriology  2009;191(7):2257-2265.
Lateral gene transfer is a significant contributor to the ongoing evolution of many bacterial pathogens, including β-hemolytic streptococci. Here we provide the first characterization of a novel integrative conjugative element (ICE), ICESde3396, from Streptococcus dysgalactiae subsp. equisimilis (group G streptococcus [GGS]), a bacterium commonly found in the throat and skin of humans. ICESde3396 is 64 kb in size and encodes 66 putative open reading frames. ICESde3396 shares 38 open reading frames with a putative ICE from Streptococcus agalactiae (group B streptococcus [GBS]), ICESa2603. In addition to genes involves in conjugal processes, ICESde3396 also carries genes predicted to be involved in virulence and resistance to various metals. A major feature of ICESde3396 differentiating it from ICESa2603 is the presence of an 18-kb internal recombinogenic region containing four unique gene clusters, which appear to have been acquired from streptococcal and nonstreptococcal bacterial species. The four clusters include two cadmium resistance operons, an arsenic resistance operon, and genes with orthologues in a group A streptococcus (GAS) prophage. Streptococci that naturally harbor ICESde3396 have increased resistance to cadmium and arsenate, indicating the functionality of genes present in the 18-kb recombinogenic region. By marking ICESde3396 with a kanamycin resistance gene, we demonstrate that the ICE is transferable to other GGS isolates as well as GBS and GAS. To investigate the presence of the ICE in clinical streptococcal isolates, we screened 69 isolates (30 GGS, 19 GBS, and 20 GAS isolates) for the presence of three separate regions of ICESde3396. Eleven isolates possessed all three regions, suggesting they harbored ICESde3396-like elements. Another four isolates possessed ICESa2603-like elements. We propose that ICESde3396 is a mobile genetic element that is capable of acquiring DNA from multiple bacterial sources and is a vehicle for dissemination of this DNA through the wider β-hemolytic streptococcal population.
PMCID: PMC2655516  PMID: 19168609
2.  Phage 3396 from a Streptococcus dysgalactiae subsp. equisimilis Pathovar May Have Its Origins in Streptococcus pyogenes▿ †  
Journal of Bacteriology  2007;189(7):2646-2652.
Streptococcus dysgalactiae subsp. equisimilis strains (group G streptococcus [GGS]) are largely defined as commensal organisms, which are closely related to the well-defined human pathogen, the group A streptococcus (GAS). While lateral gene transfers are emerging as a common theme in these species, little is known about the mechanisms and role of these transfers and their effect on the population structure of streptococci in nature. It is now becoming evident that bacteriophages are major contributors to the genotypic diversity of GAS and, consequently, are pivotal to the GAS strain structure. Furthermore, bacteriophages are strongly associated with altering the pathogenic potential of GAS. In contrast, little is know about phages from GGS and their role in the population dynamics of GGS. In this study we report the first complete genome sequence of a GGS phage, Φ3396. Exhibiting high homology to the GAS phage Φ315.1, the chimeric nature of Φ3396 is unraveled to reveal evidence of extensive ongoing genetic diversity and dissemination of streptococcal phages in nature. Furthermore, we expand on our recent findings to identify inducible Φ3396 homologues in GAS from a region of endemicity for GAS and GGS infection. Together, these findings provide new insights into not only the population structure of GGS but also the overall population structure of the streptococcal genus and the emergence of pathogenic variants.
PMCID: PMC1855781  PMID: 17259318
3.  BASys: a web server for automated bacterial genome annotation 
Nucleic Acids Research  2005;33(Web Server issue):W455-W459.
BASys (Bacterial Annotation System) is a web server that supports automated, in-depth annotation of bacterial genomic (chromosomal and plasmid) sequences. It accepts raw DNA sequence data and an optional list of gene identification information and provides extensive textual annotation and hyperlinked image output. BASys uses >30 programs to determine ∼60 annotation subfields for each gene, including gene/protein name, GO function, COG function, possible paralogues and orthologues, molecular weight, isoelectric point, operon structure, subcellular localization, signal peptides, transmembrane regions, secondary structure, 3D structure, reactions and pathways. The depth and detail of a BASys annotation matches or exceeds that found in a standard SwissProt entry. BASys also generates colorful, clickable and fully zoomable maps of each query chromosome to permit rapid navigation and detailed visual analysis of all resulting gene annotations. The textual annotations and images that are provided by BASys can be generated in ∼24 h for an average bacterial chromosome (5 Mb). BASys annotations may be viewed and downloaded anonymously or through a password protected access system. The BASys server and databases can also be downloaded and run locally. BASys is accessible at .
PMCID: PMC1160269  PMID: 15980511
4.  MovieMaker: a web server for rapid rendering of protein motions and interactions 
Nucleic Acids Research  2005;33(Web Server issue):W358-W362.
MovieMaker is a web server that allows short (∼10 s), downloadable movies of protein motions to be generated. It accepts PDB files or PDB accession numbers as input and automatically calculates, renders and merges the necessary image files to create colourful animations covering a wide range of protein motions and other dynamic processes. Users have the option of animating (i) simple rotation, (ii) morphing between two end-state conformers, (iii) short-scale, picosecond vibrations, (iv) ligand docking, (v) protein oligomerization, (vi) mid-scale nanosecond (ensemble) motions and (vii) protein folding/unfolding. MovieMaker does not perform molecular dynamics calculations. Instead it is an animation tool that uses a sophisticated superpositioning algorithm in conjunction with Cartesian coordinate interpolation to rapidly and automatically calculate the intermediate structures needed for many of its animations. Users have extensive control over the rendering style, structure colour, animation quality, background and other image features. MovieMaker is intended to be a general-purpose server that allows both experts and non-experts to easily generate useful, informative protein animations for educational and illustrative purposes. MovieMaker is accessible at .
PMCID: PMC1160245  PMID: 15980488
5.  SuperPose: a simple server for sophisticated structural superposition 
Nucleic Acids Research  2004;32(Web Server issue):W590-W594.
The SuperPose web server rapidly and robustly calculates both pairwise and multiple protein structure superpositions using a modified quaternion eigenvalue approach. SuperPose generates sequence alignments, structure alignments, PDB (Protein Data Bank) coordinates and RMSD statistics, as well as difference distance plots and images (both static and interactive) of the superimposed molecules. SuperPose employs a simple interface that requires only PDB files or accession numbers as input. All other superposition decisions are made by the program. SuperPose is uniquely able to superimpose structures that differ substantially in sequence, size or shape. It is also capable of handling a much larger range of superposition queries and situations than many standalone programs and yields results that are intuitively more in agreement with known biological or structural data. The SuperPose web server is freely accessible at
PMCID: PMC441615  PMID: 15215457

Results 1-5 (5)