Summary: Beta-ketoacyl synthase, N-terminal domain
Beta-ketoacyl synthase, N-terminal domain Provide feedback
The structure of beta-ketoacyl synthase is similar to that of the thiolase family (PF00108) and also chalcone synthase. The active site of beta-ketoacyl synthase is located between the N and C-terminal domains. The N-terminal domain contains most of the structures involved in dimer formation and also the active site cysteine .
Huang W, Jia J, Edwards P, Dehesh K, Schneider G, Lindqvist Y; , EMBO J 1998;17:1183-1191.: Crystal structure of beta-ketoacyl-acyl carrier protein synthase II from E.coli reveals the molecular architecture of condensing enzymes. PUBMED:9482715 EPMC:9482715
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This tab holds annotation information from the InterPro database.
InterPro entry IPR014030
Beta-ketoacyl-ACP synthase EC (KAS) [PUBMED:3076376] is the enzyme that catalyzes the condensation of malonyl-ACP with the growing fatty acid chain. It is found as a component of a number of enzymatic systems, including fatty acid synthetase (FAS), which catalyzes the formation of long-chain fatty acids from acetyl-CoA, malonyl-CoA and NADPH; the multi-functional 6-methysalicylic acid synthase (MSAS) from Penicillium patulum [PUBMED:2209605], which is involved in the biosynthesis of a polyketide antibiotic; polyketide antibiotic synthase enzyme systems; Emericella nidulans multifunctional protein Wa, which is involved in the biosynthesis of conidial green pigment; Rhizobium nodulation protein nodE, which probably acts as a beta-ketoacyl synthase in the synthesis of the nodulation Nod factor fatty acyl chain; and yeast mitochondrial protein CEM1. The condensation reaction is a two step process, first the acyl component of an activated acyl primer is transferred to a cysteine residue of the enzyme and is then condensed with an activated malonyl donor with the concomitant release of carbon dioxide.
This entry represents the N-terminal domain of beta-ketoacyl-ACP synthases.
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Thiolases are ubiquitous and form a large superfamily. Thiolases can function either degradatively, in the beta-oxidation pathway of fatty acids, or biosynthetically. Biosynthetic thiolases catalyse the formation of acetoacetyl-CoA from two molecules of acetyl-CoA . This is one of the fundamental categories of carbon skeletal assembly patterns in biological systems and is the first step in a wide range of biosynthetic pathways . Thiolase are usually dimeric or tetrameric enzymes. Within each monomer there are two similar domains related by pseudo dyad. The N-terminal of these two domains contains a large insertion of about 100 amino acids.
The clan contains the following 13 members:ACP_syn_III ACP_syn_III_C Chal_sti_synt_C Chal_sti_synt_N FAE1_CUT1_RppA HMG_CoA_synt_C HMG_CoA_synt_N ketoacyl-synt Ketoacyl-synt_2 Ketoacyl-synt_C SpoVAD Thiolase_C Thiolase_N
We make a range of alignments for each Pfam-A family:
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Curation and family details
|Author:||Sonnhammer ELL, Griffiths-Jones SR|
|Number in seed:||82|
|Number in full:||101410|
|Average length of the domain:||218.70 aa|
|Average identity of full alignment:||28 %|
|Average coverage of the sequence by the domain:||21.03 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 80369284 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||22|
|Download:||download the raw HMM for this family|
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There are 9 interactions for this family. More...
We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the ketoacyl-synt domain has been found. There are 257 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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