Analyses of six homologous proteins of Protochlamydia amoebophila UWE25 encoded by large GC-rich genes (lgr): a model of evolution and concatenation of leucine-rich repeats.

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Serval ID
serval:BIB_84285CD4D328
Type
Article: article from journal or magazin.
Collection
Publications
Title
Analyses of six homologous proteins of Protochlamydia amoebophila UWE25 encoded by large GC-rich genes (lgr): a model of evolution and concatenation of leucine-rich repeats.
Journal
BMC evolutionary biology
Author(s)
Eugster M., Roten C.A., Greub G.
ISSN
1471-2148[electronic]
Publication state
Published
Issued date
2007
Volume
7
Pages
231
Language
english
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov't - Publication Status: epublish
Abstract
BACKGROUND: Along the chromosome of the obligate intracellular bacteria Protochlamydia amoebophila UWE25, we recently described a genomic island Pam100G. It contains a tra unit likely involved in conjugative DNA transfer and lgrE, a 5.6-kb gene similar to five others of P. amoebophila: lgrA to lgrD, lgrF. We describe here the structure, regulation and evolution of these proteins termed LGRs since encoded by "Large G+C-Rich" genes. RESULTS: No homologs to the whole protein sequence of LGRs were found in other organisms. Phylogenetic analyses suggest that serial duplications producing the six LGRs occurred relatively recently and nucleotide usage analyses show that lgrB, lgrE and lgrF were relocated on the chromosome. The C-terminal part of LGRs is homologous to Leucine-Rich Repeats domains (LRRs). Defined by a cumulative alignment score, the 5 to 18 concatenated octacosapeptidic (28-meric) LRRs of LGRs present all a predicted alpha-helix conformation. Their closest homologs are the 28-residue RI-like LRRs of mammalian NODs and the 24-meres of some Ralstonia and Legionella proteins. Interestingly, lgrE, which is present on Pam100G like the tra operon, exhibits Pfam domains related to DNA metabolism. CONCLUSION: Comparison of the LRRs, enable us to propose a parsimonious evolutionary scenario of these domains driven by adjacent concatenations of LRRs. Our model established on bacterial LRRs can be challenged in eucaryotic proteins carrying less conserved LRRs, such as NOD proteins and Toll-like receptors.
Keywords
Amino Acid Motifs, Bacterial Proteins, Chlamydiales, Evolution, Molecular, GC Rich Sequence, Genes, Bacterial, Genomic Islands, Leucine, Proteins, Repetitive Sequences, Amino Acid, Sequence Alignment, Sequence Homology, Amino Acid
Pubmed
Web of science
Open Access
Yes
Create date
04/02/2008 20:40
Last modification date
08/05/2019 21:18
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