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Catalytic Site Atlas

CSA LITERATURE entry for 1f7l

E.C. nameholo-[acyl-carrier-protein] synthase
SpeciesBacillus subtilis (Bacteria)
E.C. Number (IntEnz)
CSA Homologues of 1f7lThere are 13 Homologs
CSA Entries With UniProtID P96618
CSA Entries With EC Number
PDBe Entry 1f7l
PDBSum Entry 1f7l
MACiE Entry M0152

Literature Report

IntroductionHolo-(acyl carrier protein) synthase (AcpS) from Bacillus subtilis post-translationally modifies ACP to its holo form in order to activate it. AcpS catalyses the transfer of the 4'-phosphopantetheinyl (P-pant) moiety of coenzyme A to a serine residue on the ACP. This gives the activated ACP enzyme and Adenosine 3'5'-bisphosphate as products. This process is important as ACP enzymes play important roles in a number of biosynthetic pathways, such as the synthesis of fatty acids and of vitamins.
Mechansim1. Water is activated by removal of a proton by either another water molecule, or Asp 35 of ACP. 2. This water then removes the hydroxyl hydrogen from Ser 36 of ACP, which then carries out the nucleophilic attack on the beta-phosphate of coenzyme A (CoA), resulting in the transfer of the P-pant group to Ser 36. 3. The resulting negatively charged 3',5'-ADP is stabilised by interactions with magnesium, Lys 62 and the His 105 main-chain amide. 4. A proton is then transferred to 3',5'-ADP from either a water molecule, or by Lys 62.

Catalytic Sites for 1f7l

Annotated By Reference To The Literature - Site 3 (Perform Site Search)
ResidueChainNumberUniProtKB NumberFunctional PartFunctionTargetDescription
LysA6262macie:sideChainHelps to stabilise the negatively charged 3',5'-ADP.
HisA105105macie:mainChainAmideThe main-chain amide of His 105 stabilises the negatively charged 3',5'-ADP.

Literature References

Notes:It is not known whether the negatively charged 3',5'-ADP is protonated by a water molecule, or by Lys 62. Therefore Lys 62 could be acting as an acid as well as being charge stabilising.
Parris KD
Crystal structures of substrate binding to Bacillus subtilis holo-(acyl carrier protein) synthase reveal a novel trimeric arrangement of molecules resulting in three active sites.
Structure 2000 8 883-895
PubMed: 10997907