title: Characterisation of a large family of polymorphic collagen-like proteins in the endospore-forming bacterium Pasteuria ramosa.
abstract: Collagen-like proteins containing glycine-X-Y repeats have been identified in several pathogenic bacteria potentially involved in virulence. Recently, a collagen-like surface protein, Pcl1a, was identified in Pasteuria ramosa, a spore-forming parasite of Daphnia. Here we characterise 37 novel putative P. ramosa collagen-like protein genes (PCLs). PCR amplification and sequencing across 10 P. ramosa strains showed they were polymorphic, distinguishing genotypes matching known differences in Daphnia/P. ramosa interaction specificity. Thirty PCLs could be divided into four groups based on sequence similarity, conserved N- and C-terminal regions and G-X-Y repeat structure. Group 1, Group 2 and Group 3 PCLs formed triplets within the genome, with one member from each group represented in each triplet. Maximum-likelihood trees suggested that these groups arose through multiple instances of triplet duplication. For Group 1, 2, 3 and 4 PCLs, X was typically proline and Y typically threonine, consistent with other bacterial collagen-like proteins. The amino acid composition of Pcl2 closely resembled Pcl1a, with X typically being glutamic acid or aspartic acid and Y typically being lysine or glutamine. Pcl2 also showed sequence similarity to Pcl1a and contained a predicted signal peptide, cleavage site and transmembrane domain, suggesting that it is a surface protein.
authors: School of Biotechnology and Biomolecular Science, University of New South Wales, Sydney, New South Wales 2052, Australia. kerensa@unsw.edu.au
authors: Kerensa
authors: K
authors: McElroy
authors: Laurence
authors: L
authors: Mouton
authors: Louis
authors: L
authors: Du Pasquier
authors: Weihong
authors: W
authors: Qi
authors: Dieter
authors: D
authors: Ebert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D003621:Daphnia / Q000382:microbiology*; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology / Q000662:veterinary*; D008969:Molecular Sequence Data; D005810:Multigene Family; D058676:Pasteuria / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins