TY - JOUR
T1 - A new enzyme superfamily - The phosphopantetheinyl transferases
AU - Lambalot, Ralph H.
AU - Gehring, Amy M.
AU - Flugel, Roger S.
AU - Zuber, Peter
AU - LaCelle, Michael
AU - Marahiel, Mohamed A.
AU - Reid, Ralph
AU - Khosla, Chaitan
AU - Walsh, Christopher T.
N1 - Funding Information:
The authors thank Professor William Strohl (Ohio State University) for sharing the S. acfuosirs NshC protein sequence prior to publication. This work was supported by National Institutes of Health grants GM2001 1 (CTW), GM45898 (PZ) CA66736 (CK) and 5P32-GM0631307 {RSF). CK was also supported by grant MCB-941741 Q from the National Science Foundation. MAM was supported by the Deutsche Forschungsgemeinschaft and the European Commission. RHL was supported by National Institutes of Health Post-Doctoral Fellowship GM1 658303. AMG is a Howard Hughes Medical institute Predoctoral Fellow.
PY - 1996
Y1 - 1996
N2 - Background: All polyketide synthases, fatty acid synthases, and non- ribosomal peptide synthetases require posttranslational modification of their constituent acyl carrier protein domain(s) to become catalytically active. The inactive apoproteins are converted to their active holo-forms by posttranslational transfer of the 4'-phosphopantetheinyl (P-pant) moiety of coenzyme A to the sidechain hydroxyl of a conserved serine residue in each acyl carrier protein domain. The first P-pant transferase to be cloned and characterized was the recently reported Escherichia coli enzyme ACPS, responsible for apo to holo conversion of fatty acid synthase. Surprisingly, initial searches of sequence databases did not reveal any proteins with significant peptide sequence similarity with ACPS. Results: Through refinement of sequence alignments that indicated low level similarity with the ACPS peptide sequence, we identified two consensus motifs shared among several potential ACPS homologs. This has led to the identification of a large family of proteins having 12-22% similarity with ACPS, which are putative P-pant transferases. Three of these proteins, E. coli EntD and o195, and B. subtilis Sfp, have been overproduced, purified and found to have P- pant transferase activity, confirming that the observed low level of sequence homology correctly predicted catalytic function. Three P-pant transferases are now known to be present in E. coli (ACPS, EntD and o 195); ACPS and EntD are specific for the activation of fatty acid synthase and enterobactin synthetase, respectively. The ape-protein substrate for o195 has not yet been identified. Sfp is responsible for the activation of the surfactin synthetase. Conclusions: The specificity of ACPS and EntD for distinct P- pant-requiring enzymes suggests that each P-pant-requiring synthase has its own partner enzyme responsible for apo to holo activation of its acyl carrier domains. This is the first direct evidence that in organisms containing multiple P-pant-requiring pathways, each pathway has its own posttranslational modifying activity.
AB - Background: All polyketide synthases, fatty acid synthases, and non- ribosomal peptide synthetases require posttranslational modification of their constituent acyl carrier protein domain(s) to become catalytically active. The inactive apoproteins are converted to their active holo-forms by posttranslational transfer of the 4'-phosphopantetheinyl (P-pant) moiety of coenzyme A to the sidechain hydroxyl of a conserved serine residue in each acyl carrier protein domain. The first P-pant transferase to be cloned and characterized was the recently reported Escherichia coli enzyme ACPS, responsible for apo to holo conversion of fatty acid synthase. Surprisingly, initial searches of sequence databases did not reveal any proteins with significant peptide sequence similarity with ACPS. Results: Through refinement of sequence alignments that indicated low level similarity with the ACPS peptide sequence, we identified two consensus motifs shared among several potential ACPS homologs. This has led to the identification of a large family of proteins having 12-22% similarity with ACPS, which are putative P-pant transferases. Three of these proteins, E. coli EntD and o195, and B. subtilis Sfp, have been overproduced, purified and found to have P- pant transferase activity, confirming that the observed low level of sequence homology correctly predicted catalytic function. Three P-pant transferases are now known to be present in E. coli (ACPS, EntD and o 195); ACPS and EntD are specific for the activation of fatty acid synthase and enterobactin synthetase, respectively. The ape-protein substrate for o195 has not yet been identified. Sfp is responsible for the activation of the surfactin synthetase. Conclusions: The specificity of ACPS and EntD for distinct P- pant-requiring enzymes suggests that each P-pant-requiring synthase has its own partner enzyme responsible for apo to holo activation of its acyl carrier domains. This is the first direct evidence that in organisms containing multiple P-pant-requiring pathways, each pathway has its own posttranslational modifying activity.
KW - ACP
KW - acyl carrier protein
KW - biosynthesis
KW - non-ribosomal peptide synthetase
KW - phosphopantetheine
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U2 - 10.1016/S1074-5521(96)90181-7
DO - 10.1016/S1074-5521(96)90181-7
M3 - Article
C2 - 8939709
AN - SCOPUS:0030294470
SN - 1074-5521
VL - 3
SP - 923
EP - 936
JO - Chemistry and Biology
JF - Chemistry and Biology
IS - 11
ER -