Homepeptide repeats: implications for protein structure, function and evolution.
Analysis of protein sequences from Mycobacterium tuberculosis H37Rv (Mtb H37Rv) was performed to identify homopeptide repeat-containing proteins (HRCPs). Functional annotation of the HRCPs showed that they are preferentially involved in cellular metabolism. Furthermore, these homopeptide repeats might play some specific roles in protein-protein interaction. Repeat length differences among Bacteria, Archaea and Eukaryotes were calculated in order to identify the conservation of the repeats in these divergent kingdoms. From the results, it was evident that these repeats have a higher degree of conservation in Bacteria and Archaea than in Eukaryotes. In addition, there seems to be a direct correlation between the repeat length difference and the degree of divergence between the species. Our study supports the hypothesis that the presence of homopeptide repeats influences the rate of evolution of the protein sequences in which they are embedded. Thus, homopeptide repeat may have structural, functional and evolutionary implications on proteins.
Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore, India.
Muthukumarasamy
M
Uthayakumar
Bowdadu
B
Benazir
Sanjeev
S
Patra
Marthandan Kirti
MK
Vaishnavi
Manickam
M
Gurusaran
Kanagarajan
K
Sureka
Jeyaraman
J
Jeyakanthan
Kanagaraj
K
Sekar
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D019843:Archaeal Proteins / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005075:Biological Evolution; D004926:Escherichia coli / Q000737:chemistry; D019143:Evolution, Molecular; D006801:Humans; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry; D020449:Repetitive Sequences, Amino Acid; D020539:Sequence Analysis, Protein; D016945:Sulfolobus acidocaldarius / Q000737:chemistry
D000596:Amino Acids; D019843:Archaeal Proteins; D001426:Bacterial Proteins; D010455:Peptides; D011506:Proteins