Molecular modeling studies of the conserved B(12)-binding motif and its variants from Clostridium tetanomorphum glutamate mutase.
The coupling of an aspartate residue with an active site histidine plays a pivotal role in enzyme catalysis. The His-Asp pair in glutamate mutase and other B(12)-dependent mutases is not only responsible for coenzyme-binding, but is also involved in fine-tuning the enzymatic activities. Our modeling results show that the His-Asp pair is arranged in a highly organized manner. Except for carboxymethylated Cys or Glu, a less hindered or non-charged amino acid residue is preferred between the conserved histidine and aspartate residue.
Hsu
Chun-Hua
CH
Department of Agricultural Chemistry, National Taiwan University, Taipei, Taiwan. andyhsu@ntu.edu.tw
Chen
Hao-Ping
HP
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites; D048012:Clostridium tetanomorphum / Q000201:enzymology*; D017124:Conserved Sequence; D019751:Intramolecular Transferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D056004:Molecular Dynamics Simulation; D014805:Vitamin B 12 / Q000737:chemistry / Q000378:metabolism*
D001426:Bacterial Proteins; D019751:Intramolecular Transferases; C021570:methylaspartate mutase; D014805:Vitamin B 12