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Nucleic Acids Res. 1993 March 11; 21(5): 1193–1198.
PMCID: PMC309281

The pre-mRNA binding K protein contains a novel evolutionarily conserved motif.


The K protein is among the major pre-mRNA-binding proteins (hnRNPs) in vertebrate cell nuclei. It binds tenaciously to cytidine-rich sequences and is the major oligo(rC/dC)-binding protein in vertebrate cells. We have cloned a cDNA of the Xenopus laevis hnRNP K and determined its sequence. The X.laevis hnRNP K is a 47 kD protein that is remarkably similar to its human 66 kD counterpart except for two large internal deletions. The sequence of hnRNP K contains a 45 amino acid repeated motif which is almost completely conserved between the X.laevis and human proteins. We found that this repeated motif, the KH motif (for K homology), shows significant homology to several proteins some of which are known nucleic acids binding proteins. The homology is particularly strong with the archeabacterial ribosomal protein S3 and with the saccharomyces cerevisiae protein MER1 which is required for meiosis-specific splicing of the MER 2 transcript. As several of the proteins that contain the KH motif are known to bind RNA, this domain may be involved in RNA binding.

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  • Dreyfuss G, Swanson MS, Piñol-Roma S. Heterogeneous nuclear ribonucleoprotein particles and the pathway of mRNA formation. Trends Biochem Sci. 1988 Mar;13(3):86–91. [PubMed]
  • Piñol-Roma S, Dreyfuss G. Shuttling of pre-mRNA binding proteins between nucleus and cytoplasm. Nature. 1992 Feb 20;355(6362):730–732. [PubMed]
  • Swanson MS, Dreyfuss G. Classification and purification of proteins of heterogeneous nuclear ribonucleoprotein particles by RNA-binding specificities. Mol Cell Biol. 1988 May;8(5):2237–2241. [PMC free article] [PubMed]
  • Matunis MJ, Michael WM, Dreyfuss G. Characterization and primary structure of the poly(C)-binding heterogeneous nuclear ribonucleoprotein complex K protein. Mol Cell Biol. 1992 Jan;12(1):164–171. [PMC free article] [PubMed]
  • Bandziulis RJ, Swanson MS, Dreyfuss G. RNA-binding proteins as developmental regulators. Genes Dev. 1989 Apr;3(4):431–437. [PubMed]
  • Frankel AD, Mattaj IW, Rio DC. RNA-protein interactions. Cell. 1991 Dec 20;67(6):1041–1046. [PubMed]
  • Kenan DJ, Query CC, Keene JD. RNA recognition: towards identifying determinants of specificity. Trends Biochem Sci. 1991 Jun;16(6):214–220. [PubMed]
  • Christensen ME, Fuxa KP. The nucleolar protein, B-36, contains a glycine and dimethylarginine-rich sequence conserved in several other nuclear RNA-binding proteins. Biochem Biophys Res Commun. 1988 Sep 30;155(3):1278–1283. [PubMed]
  • Dreyfuss G, Adam SA, Choi YD. Physical change in cytoplasmic messenger ribonucleoproteins in cells treated with inhibitors of mRNA transcription. Mol Cell Biol. 1984 Mar;4(3):415–423. [PMC free article] [PubMed]
  • O'Farrell PZ, Goodman HM, O'Farrell PH. High resolution two-dimensional electrophoresis of basic as well as acidic proteins. Cell. 1977 Dec;12(4):1133–1141. [PubMed]
  • Choi YD, Dreyfuss G. Monoclonal antibody characterization of the C proteins of heterogeneous nuclear ribonucleoprotein complexes in vertebrate cells. J Cell Biol. 1984 Dec;99(6):1997–1204. [PMC free article] [PubMed]
  • Dreyfuss G, Choi YD, Adam SA. Characterization of heterogeneous nuclear RNA-protein complexes in vivo with monoclonal antibodies. Mol Cell Biol. 1984 Jun;4(6):1104–1114. [PMC free article] [PubMed]
  • Piñol-Roma S, Swanson MS, Gall JG, Dreyfuss G. A novel heterogeneous nuclear RNP protein with a unique distribution on nascent transcripts. J Cell Biol. 1989 Dec;109(6 Pt 1):2575–2587. [PMC free article] [PubMed]
  • Spiridonova VA, Akhmanova AS, Kagramanova VK, Köpke AK, Mankin AS. Ribosomal protein gene cluster of Halobacterium halobium: nucleotide sequence of the genes coding for S3 and L29 equivalent ribosomal proteins. Can J Microbiol. 1989 Jan;35(1):153–159. [PubMed]
  • Engebrecht J, Roeder GS. MER1, a yeast gene required for chromosome pairing and genetic recombination, is induced in meiosis. Mol Cell Biol. 1990 May;10(5):2379–2389. [PMC free article] [PubMed]
  • Engebrecht J, Hirsch J, Roeder GS. Meiotic gene conversion and crossing over: their relationship to each other and to chromosome synapsis and segregation. Cell. 1990 Sep 7;62(5):927–937. [PubMed]
  • Brauer D, Röming R. The primary structure of protein S3 from the small ribosomal subunit of Escherichia coli. FEBS Lett. 1979 Oct 15;106(2):352–357. [PubMed]
  • Régnier P, Grunberg-Manago M, Portier C. Nucleotide sequence of the pnp gene of Escherichia coli encoding polynucleotide phosphorylase. Homology of the primary structure of the protein with the RNA-binding domain of ribosomal protein S1. J Biol Chem. 1987 Jan 5;262(1):63–68. [PubMed]
  • Delahodde A, Becam AM, Perea J, Jacq C. A yeast protein HX has homologies with the histone H2AF expressed in chicken embryo. Nucleic Acids Res. 1986 Nov 25;14(22):9213–9214. [PMC free article] [PubMed]
  • Möller W, Amons R. Phosphate-binding sequences in nucleotide-binding proteins. FEBS Lett. 1985 Jul 1;186(1):1–7. [PubMed]
  • Saraste M, Sibbald PR, Wittinghofer A. The P-loop--a common motif in ATP- and GTP-binding proteins. Trends Biochem Sci. 1990 Nov;15(11):430–434. [PubMed]
  • Pearson WR. Rapid and sensitive sequence comparison with FASTP and FASTA. Methods Enzymol. 1990;183:63–98. [PubMed]
  • Feng DF, Doolittle RF. Progressive sequence alignment as a prerequisite to correct phylogenetic trees. J Mol Evol. 1987;25(4):351–360. [PubMed]
  • Rinke-Appel J, Jünke N, Stade K, Brimacombe R. The path of mRNA through the Escherichia coli ribosome; site-directed cross-linking of mRNA analogues carrying a photo-reactive label at various points 3' to the decoding site. EMBO J. 1991 Aug;10(8):2195–2202. [PubMed]
  • Engebrecht JA, Voelkel-Meiman K, Roeder GS. Meiosis-specific RNA splicing in yeast. Cell. 1991 Sep 20;66(6):1257–1268. [PubMed]
  • Dreyfuss G. Structure and function of nuclear and cytoplasmic ribonucleoprotein particles. Annu Rev Cell Biol. 1986;2:459–498. [PubMed]
  • Choi YD, Dreyfuss G. Isolation of the heterogeneous nuclear RNA-ribonucleoprotein complex (hnRNP): a unique supramolecular assembly. Proc Natl Acad Sci U S A. 1984 Dec;81(23):7471–7475. [PubMed]
  • Piñol-Roma S, Choi YD, Matunis MJ, Dreyfuss G. Immunopurification of heterogeneous nuclear ribonucleoprotein particles reveals an assortment of RNA-binding proteins. Genes Dev. 1988 Feb;2(2):215–227. [PubMed]
  • Chung SY, Wooley J. Set of novel, conserved proteins fold pre-messenger RNA into ribonucleosomes. Proteins. 1986 Nov;1(3):195–210. [PubMed]

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