Escherichia coli K-12 substr. MG1655 Enzyme: holo-[acyl-carrier-protein] synthase

Gene: acpS Accession Numbers: EG10247 (EcoCyc), b2563, ECK2561

Synonyms: dpj

Regulation Summary Diagram: ?

Regulation summary diagram for acpS

Subunit composition of holo-[acyl-carrier-protein] synthase = [AcpS]2

The acpS gene encodes holo-[ACP] synthase, which transfers the 4-phosphopantetheine moiety of CoA to the apo-ACP to form holo-ACP, the active form of the carrier in lipid synthesis [Lambalot95, Elovson68, Polacco81]. The enzyme is an AcpS homodimer [Lambalot95].

The acpS gene is essential for viability [Takiff92, Lam92]. An acpS mutant exhibits growth dependence on supplementation of the media with high levels of pantothenate [Polacco81]. Decreased holo-ACP abundance does not affect the rate of incorporation of oleic acid into phospholipid [Cronan84]. A conditional acpS mutant (MP4 strain) exhibits an abnormally low ratio of holo-ACP to apo-ACP under permissive as well as restrictive conditions, whereas the ratio of phospholipid to protein content is similar to wild type, indicating that the holo-ACP to apo-ACP ratio is not critical for the maintenance of lipid abundance [Jackowski83]. This conditional acpS1 mutation from the MP4 strain specifies a G4D change, which decreases enzyme efficiency by 5-fold [Flugel00]. The heat sensitivity of an acpS1 mutant is suppressed by overproduction of YhhU [Flugel00]. Suppressors of acpS reduction-of-function mutations include lon mutations [Lam92].

AcpS is a member of a 4'-phosphopantetheinyl transferase (P-pant transferase, or PPTase) protein family (including E. coli EntD, E. coli o195 protein, and Bacillus subtilis Sfp) that shares two conserved motifs but shares relatively low sequence identity overall [Lambalot96]. The phenotype of an E. coli acpS mutant is functionally complemented by Streptococcus pneumoniae AcpS [McAllister00], Bacillus subtilis AcpS (encoded by ydcB) [Mootz01], Bacillus subtilis Sfp [Mootz01], or Bacillus brevis Gsp [Mootz01].

Regulation has been described [Matsunaga96].

Locations: cytosol

Map Position: [2,698,640 <- 2,699,020] (58.16 centisomes, 209°)
Length: 381 bp / 126 aa

Molecular Weight of Polypeptide: 14.052 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0008433 , DIP:DIP-9047N , EchoBASE:EB0243 , EcoGene:EG10247 , EcoliWiki:b2563 , Mint:MINT-1256571 , ModBase:P24224 , OU-Microarray:b2563 , PortEco:acpS , PR:PRO_000022046 , Pride:P24224 , Protein Model Portal:P24224 , RefSeq:NP_417058 , RegulonDB:EG10247 , SMR:P24224 , String:511145.b2563 , UniProt:P24224

Relationship Links: InterPro:IN-FAMILY:IPR002582 , InterPro:IN-FAMILY:IPR004568 , InterPro:IN-FAMILY:IPR008278 , Pfam:IN-FAMILY:PF01648 , ProDom:IN-FAMILY:PD004282

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Instance reaction of [an acyl-carrier protein + coenzyme A → adenosine 3',5'-bisphosphate + a holo-[acyl-carrier protein] + H+] (
i1: [EntB aryl-carrier protein] + coenzyme A → a holo-[EntB isochorismatase/aryl-carrier protein] + adenosine 3',5'-bisphosphate + H+ (

GO Terms:

Biological Process: GO:0018070 - peptidyl-serine phosphopantetheinylation Inferred from experiment [MAJERUS65]
GO:0006629 - lipid metabolic process Inferred by computational analysis [UniProtGOA11a]
GO:0006631 - fatty acid metabolic process Inferred by computational analysis [UniProtGOA11a]
GO:0006633 - fatty acid biosynthetic process Author statement Inferred by computational analysis [UniProtGOA11a, GOA06, GOA01a, Lambalot95]
Molecular Function: GO:0008897 - holo-[acyl-carrier-protein] synthase activity Inferred from experiment Inferred by computational analysis [GOA06, GOA01, GOA01a, Lambalot95]
GO:0000287 - magnesium ion binding Inferred by computational analysis [GOA06, GOA01a]
GO:0016740 - transferase activity Author statement Inferred by computational analysis [UniProtGOA11a, Lambalot95]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11a]
Cellular Component: GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA06]
GO:0005829 - cytosol Inferred by computational analysis [DiazMejia09]

MultiFun Terms: metabolism biosynthesis of building blocks fatty acids and phosphatidic acid

Essentiality data for acpS knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB Lennox No 37 Aerobic 7   No [Baba06, Comment 1]

Enzymatic reaction of: holo-[acyl-carrier-protein] synthase

Synonyms: CoA:apo-ACP pantetheinephosphotransferase, ACP synthetase, ACPS, holo-ACP synthase

EC Number:

an acyl-carrier protein + coenzyme A <=> adenosine 3',5'-bisphosphate + a holo-[acyl-carrier protein] + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: superpathway of chorismate metabolism , enterobactin biosynthesis , acyl carrier protein metabolism I

The holo-ACP synthase enzyme transfers the 4-phosphopantetheine moeity of CoA to the apo-ACP to form holo-ACP, which is the active form of the carrier in lipid synthesis [Elovson68, Polacco81]. The enzyme is an AcpS homodimer [Lambalot95].

Holo-ACP synthase shows a Km of 50 micromolar for CoA and a Km of less than 1 micromolar for apo-ACP (which becomes inhibitory at higher concentrations, over 2 micromolar) [Lambalot95]. The enzyme favors ACP substrates with greater negative charge in vitro, and it can utilize some analogs of CoA [Gehring97a].

Holo-ACP synthase exhibits activity toward various exogenous substrates, including a spinach ACP substrate [Jaworski89, Broadwater99], rat Type I fatty acid synthase ACP domain [Tropf98], Lactobacillus casei D-alanyl carrier protein (Dcp) [Debabov96], Rhizobium NodF [Ritsema98], and Streptomyces spp. polyketide synthase ACPs that catalyze formation of a number of compounds with antibiotic activity such as oxytetracycline [Gehring97a], tetracenomycin [Gehring97a], granaticin [Gehring97a, Carreras97], frenolicin [Gehring97a, Carreras97], griseusin [Cox97], and actinorhodin [Cox97, Carreras97]. Holo-ACP synthase also transfers various acylated moieties from acylated CoAs to polyketide synthase ACPs [Cox97, Carreras97].

Holo-ACP synthase has been purified using a denaturation and renaturation step [Lambalot95].

Cofactors or Prosthetic Groups: Mg2+ [Elovson68]

Alternative Cofactors for Mg2+ [Elovson68 ]: Mn2+

Inhibitors (Unknown Mechanism): apo-[acyl carrier protein] [Lambalot95, Comment 2] , ammonium sulfate [Elovson68] , potassium chloride [Elovson68]

Kinetic Parameters:

Km (μM)
kcat (sec-1)
kcat/Km (sec-1 μM-1)
coenzyme A
[Lambalot97, BRENDA14]
coenzyme A
[Prescott72, BRENDA14]
coenzyme A
[McAllister06, BRENDA14]

pH(opt): 7.5 [BRENDA14, Elovson68]

Sequence Features

Protein sequence of AcpS with features indicated

Feature Class Location Citations Comment
Cleavage-of-Initial-Methionine 1
[Lambalot95, UniProt11]
UniProt: Removed.
Chain 2 -> 126
UniProt: Holo-[acyl-carrier-protein] synthase;
Mutagenesis-Variant 5
[Flugel00, UniProt11]
UniProt: 5-fold reduction in catalytic activity.
Metal-Binding-Site 9
UniProt: Magnesium; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 58
UniProt: Magnesium; Non-Experimental Qualifier: by similarity;

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram

Transcription-unit diagram


3/2/1998 (pkarp) Merged genes G220/EG10247 and EG10247/acpS
1/26/1998 (pkarp) Merged genes G7984/acpS and EG10247/dpj


Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

BRENDA14: BRENDA team (2014). "Imported from BRENDA version existing on Aug 2014."

Broadwater99: Broadwater JA, Fox BG (1999). "Spinach holo-acyl carrier protein: overproduction and phosphopantetheinylation in Escherichia coli BL21(DE3), in vitro acylation, and enzymatic desaturation of histidine-tagged isoform I." Protein Expr Purif 15(3);314-26. PMID: 10092491

Carreras97: Carreras CW, Gehring AM, Walsh CT, Khosla C (1997). "Utilization of enzymatically phosphopantetheinylated acyl carrier proteins and acetyl-acyl carrier proteins by the actinorhodin polyketide synthase." Biochemistry 36(39);11757-61. PMID: 9305965

Cox97: Cox RJ, Hitchman TS, Byrom KJ, Findlow IS, Tanner JA, Crosby J, Simpson TJ (1997). "Post-translational modification of heterologously expressed Streptomyces type II polyketide synthase acyl carrier proteins." FEBS Lett 405(3);267-72. PMID: 9108302

Cronan84: Cronan JE (1984). "Evidence that incorporation of exogenous fatty acids into the phospholipids of Escherichia coli does not require acyl carrier protein." J Bacteriol 159(2);773-5. PMID: 6378892

Debabov96: Debabov DV, Heaton MP, Zhang Q, Stewart KD, Lambalot RH, Neuhaus FC (1996). "The D-Alanyl carrier protein in Lactobacillus casei: cloning, sequencing, and expression of dltC." J Bacteriol 178(13);3869-76. PMID: 8682792

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

Elovson68: Elovson J, Vagelos PR (1968). "Acyl carrier protein. X. Acyl carrier protein synthetase." J Biol Chem 1968;243(13);3603-11. PMID: 4872726

Flugel00: Flugel RS, Hwangbo Y, Lambalot RH, Cronan JE, Walsh CT (2000). "Holo-(acyl carrier protein) synthase and phosphopantetheinyl transfer in Escherichia coli." J Biol Chem 2000;275(2);959-68. PMID: 10625633

Gehring97a: Gehring AM, Lambalot RH, Vogel KW, Drueckhammer DG, Walsh CT (1997). "Ability of Streptomyces spp. acyl carrier proteins and coenzyme A analogs to serve as substrates in vitro for E. coli holo-ACP synthase." Chem Biol 4(1);17-24. PMID: 9070424

GOA01: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

Jackowski83: Jackowski S, Rock CO (1983). "Ratio of active to inactive forms of acyl carrier protein in Escherichia coli." J Biol Chem 258(24);15186-91. PMID: 6317688

Jaworski89: Jaworski JG, Post-Beittenmiller MA, Ohlrogge JB (1989). "Site-directed mutagenesis of the spinach acyl carrier protein-I prosthetic group attachment site." Eur J Biochem 184(3);603-9. PMID: 2553397

Lam92: Lam HM, Tancula E, Dempsey WB, Winkler ME (1992). "Suppression of insertions in the complex pdxJ operon of Escherichia coli K-12 by lon and other mutations." J Bacteriol 1992;174(5);1554-67. PMID: 1537800

Lambalot95: Lambalot RH, Walsh CT (1995). "Cloning, overproduction, and characterization of the Escherichia coli holo-acyl carrier protein synthase." J Biol Chem 1995;270(42);24658-61. PMID: 7559576

Lambalot96: Lambalot RH, Gehring AM, Flugel RS, Zuber P, LaCelle M, Marahiel MA, Reid R, Khosla C, Walsh CT (1996). "A new enzyme superfamily - the phosphopantetheinyl transferases." Chem Biol 1996;3(11);923-36. PMID: 8939709

Lambalot97: Lambalot RH, Walsh CT (1997). "Holo-[acyl-carrier-protein] synthase of Escherichia coli." Methods Enzymol 279;254-62. PMID: 9211277


Matsunaga96: Matsunaga J, Dyer M, Simons EL, Simons RW (1996). "Expression and regulation of the rnc and pdxJ operons of Escherichia coli." Mol Microbiol 22(5);977-89. PMID: 8971718

McAllister00: McAllister KA, Peery RB, Meier TI, Fischl AS, Zhao G (2000). "Biochemical and molecular analyses of the Streptococcus pneumoniae acyl carrier protein synthase, an enzyme essential for fatty acid biosynthesis." J Biol Chem 275(40);30864-72. PMID: 10903317

McAllister06: McAllister KA, Peery RB, Zhao G (2006). "Acyl carrier protein synthases from gram-negative, gram-positive, and atypical bacterial species: Biochemical and structural properties and physiological implications." J Bacteriol 188(13);4737-48. PMID: 16788183

Mootz01: Mootz HD, Finking R, Marahiel MA (2001). "4'-phosphopantetheine transfer in primary and secondary metabolism of Bacillus subtilis." J Biol Chem 276(40);37289-98. PMID: 11489886

Polacco81: Polacco ML, Cronan JE (1981). "A mutant of Escherichia coli conditionally defective in the synthesis of holo-[acyl carrier protein]." J Biol Chem 1981;256(11);5750-4. PMID: 7016860

Prescott72: Prescott DJ, Vagelos PR (1972). "Acyl carrier protein." Adv Enzymol Relat Areas Mol Biol 36;269-311. PMID: 4561013

Ritsema98: Ritsema T, Gehring AM, Stuitje AR, van der Drift KM, Dandal I, Lambalot RH, Walsh CT, Thomas-Oates JE, Lugtenberg BJ, Spaink HP (1998). "Functional analysis of an interspecies chimera of acyl carrier proteins indicates a specialized domain for protein recognition." Mol Gen Genet 257(6);641-8. PMID: 9604887

Takiff92: Takiff HE, Baker T, Copeland T, Chen SM, Court DL (1992). "Locating essential Escherichia coli genes by using mini-Tn10 transposons: the pdxJ operon." J Bacteriol 174(5);1544-53. PMID: 1537799

Tropf98: Tropf S, Revill WP, Bibb MJ, Hopwood DA, Schweizer M (1998). "Heterologously expressed acyl carrier protein domain of rat fatty acid synthase functions in Escherichia coli fatty acid synthase and Streptomyces coelicolor polyketide synthase systems." Chem Biol 5(3);135-46. PMID: 9545424

UniProt09: UniProt Consortium (2009). "UniProt version 15.8 released on 2009-10-01 00:00:00." Database.

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProt11: UniProt Consortium (2011). "UniProt version 2011-06 released on 2011-06-30 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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