Unexpected catalytic site variation in phosphoprotein phosphatase homologues of cofactor-dependent phosphoglycerate mutase.
The cofactor-dependent phosphoglycerate mutase (dPGM) superfamily contains, besides mutases, a variety of phosphatases, both broadly and narrowly substrate-specific. Distant dPGM homologues, conspicuously abundant in microbial genomes, represent a challenge for functional annotation based on sequence comparison alone. Here we carry out sequence analysis and molecular modelling of two families of bacterial dPGM homologues, one the SixA phosphoprotein phosphatases, the other containing various proteins of no known molecular function. The models show how SixA proteins have adapted to phosphoprotein substrate and suggest that the second family may also encode phosphoprotein phosphatases. Unexpected variation in catalytic and substrate-binding residues is observed in the models.
Rigden
Daniel J
DJ
Embrapa Genetic Resources and Biotechnology, Cenargen/Embrapa, Parque Estação Biológica, Final W3 Norte, 70770-900 Brasília, Brazil. daniel@cenargen.embrapa.br
D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology*; D020134:Catalytic Domain; D019143:Evolution, Molecular; D014644:Genetic Variation; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010736:Phosphoglycerate Mutase / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000737:chemistry* / Q000145:classification / Q000235:genetics*; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid
D010749:Phosphoprotein Phosphatases; D010736:Phosphoglycerate Mutase