spacer
View the latest EBI news stories and important announcements...
more

spacer
Search The CSA
PDB ID
UNIPROT ID
EC Number

Catalytic Site Atlas

CSA LITERATURE entry for 1fug

E.C. namemethionine adenosyltransferase
SpeciesEscherichia coli (Bacteria)
E.C. Number (IntEnz) 2.5.1.6
CSA Homologues of 1fugThere are 17 Homologs
CSA Entries With UniProtID P0A817
CSA Entries With EC Number 2.5.1.6
PDBe Entry 1fug
PDBSum Entry 1fug
MACiE Entry M0009

Literature Report

IntroductionIn biological systems, methyl groups are transferred from a small number of donors to a large number of acceptors. S-adenosylmethionine (AdoMet), is the most widespread of these donors, and is synthesised solely by the action of AdoMet synthase. The reaction pathway is unusual in that the triphosphate chain is cleaved from ATP as AdoMet is formed and the triphosphate is hydrolysed to PPi and Pi before the product is released. There are three similar domains arranged around a pseudo-threefold symmetry axis.
MechansimThe reaction catalysed involves the cleavage of the triphosphate chain from ATP, in forming the product, and hydrolytic cleavage of the PPPi to PPi and Pi before the AdoMet product is released. Mechanistic studies have shown the AdoMet forming reaction to be have an SN2 mechanism, with the S atom of methionine attacking the C5 atom of ATP directly. The reaction requires divalent cations for activity, and two binding sites for these have been postulated in the active site, and these are thought to be present from EPR studies. The precise catalytic mechanism is not known. The active site is formed at the interface between two monomers.
Reaction

Catalytic Sites for 1fug

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
LysA269270macie:sideChain
LysA265266macie:sideChain
AspA271272macie:sideChain
LysB245246macie:sideChain
HisB1415macie:sideChain
LysB165166macie:sideChain
ArgB244245macie:sideChain

Annotated By Reference To The Literature - Site 2 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
LysA245246macie:sideChain
HisA1415macie:sideChain
LysA165166macie:sideChain
ArgA244245macie:sideChain
LysB269270macie:sideChain
LysB265266macie:sideChain
AspB271272macie:sideChain

Literature References

Notes:
Taylor JC
The bifunctional active site of s-adenosylmethionine synthetase. Roles of the active site aspartates.
J Biol Chem 1999 274 32909-32914
PubMed: 10551856
Takusagawa F
Crystal structure of S-adenosylmethionine synthetase.
J Biol Chem 1996 271 136-147
PubMed: 8550549
Takusagawa F
Structure and function of S-adenosylmethionine synthetase: crystal structures of S-adenosylmethionine synthetase with ADP, BrADP, and PPi at 28 angstroms resolution.
Biochemistry 1996 35 2586-2596
PubMed: 8611562
Fu Z
Flexible loop in the structure of S-adenosylmethionine synthetase crystallized in the tetragonal modification.
J Biomol Struct Dyn 1996 13 727-739
PubMed: 8723769
spacer
spacer