High resolution structure of the phosphohistidine-activated form of Escherichia coli cofactor-dependent phosphoglycerate mutase.
The active conformation of the dimeric cofactor-dependent phosphoglycerate mutase (dPGM) from Escherichia coli has been elucidated by crystallographic methods to a resolution of 1.25 A (R-factor 0.121; R-free 0.168). The active site residue His(10), central in the catalytic mechanism of dPGM, is present as a phosphohistidine with occupancy of 0.28. The structural changes on histidine phosphorylation highlight various features that are significant in the catalytic mechanism. The C-terminal 10-residue tail, which is not observed in previous dPGM structures, is well ordered and interacts with residues implicated in substrate binding; the displacement of a loop adjacent to the active histidine brings previously overlooked residues into positions where they may directly influence catalysis. E. coli dPGM, like the mammalian dPGMs, is a dimer, whereas previous structural work has concentrated on monomeric and tetrameric yeast forms. We can now analyze the sequence differences that cause this variation of quaternary structure.
Bond
C S
CS
Wellcome Trust Biocentre, University of Dundee, Dundee DD1 5EH, United Kingdom.
White
M F
MF
Hunter
W N
WN
D000595:Amino Acid Sequence; D001665:Binding Sites; D004926:Escherichia coli / Q000201:enzymology*; D006639:Histidine / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010736:Phosphoglycerate Mutase / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D017510:Protein Folding; D020836:Protein Structure, Quaternary; D017386:Sequence Homology, Amino Acid
D006639:Histidine; D010736:Phosphoglycerate Mutase