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Search The CSA
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Catalytic Site Atlas

CSA LITERATURE entry for 1fwk

E.C. namehomoserine kinase
SpeciesMethanococcus jannaschii ()
E.C. Number (IntEnz) 2.7.1.39
CSA Homologues of 1fwkThere are 35 Homologs
CSA Entries With UniProtID Q58504
CSA Entries With EC Number 2.7.1.39
PDBe Entry 1fwk
PDBSum Entry 1fwk
MACiE Entry 1fwk

Literature Report

IntroductionHomoserine kinase(HSK) belongs to a large superfamily, the GHMP kinase. It catalyses the phosphorylation of L-homoserine to O-phospho-L-homoserine, the first reaction after the branching-point to methionine in the bacterial threonine biosynthetic pathway.
MechansimA transition state stabilisation mechanism which does not involved a catalytic base was proposed. Substrate binding induces conformational changes at the active site to promote the catalysis and transition state stabilisation. Mg2+ ion coordinates with the beta and gamma-phosphate of ATP. It activates the gamma-phosphate to deprotonate the delta-OH group of Hse and hence mediating the direct attack of the delta-OH group on the gamma-phosphate of ATP. The transition state is stabilised by Mg2+ ion and Thr183, which interacts with the beta-phosphate.
Reaction

Catalytic Sites for 1fwk

Annotated By Reference To The Literature - Site 1 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ThrD183179macie:sideChainIt coordinates with the beta-phosphate of ATP to stabilise the transition state.

Annotated By Reference To The Literature - Site 2 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ThrA183179macie:sideChainIt coordinates with the beta-phosphate of ATP to stabilise the transition state.

Annotated By Reference To The Literature - Site 3 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ThrB183179macie:sideChainIt coordinates with the beta-phosphate of ATP to stabilise the transition state.

Annotated By Reference To The Literature - Site 4 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
ThrC183179macie:sideChainIt coordinates with the beta-phosphate of ATP to stabilise the transition state.

Literature References

Notes:
Krishna SS
Structural basis for the catalysis and substrate specificity of homoserine kinase.
Biochemistry 2001 40 10810-10818
PubMed: 11535056
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