Synonyms: corrinoid/Fe-S protein, C/Fe-SP, E[Co]
Species: Moorella thermoacetica
Subunit composition of AcsCD corrinoid/iron-sulfur protein complex = [AcsD][AcsC]
corrinoid/iron-sulfur protein α subunit = AcsD
corrinoid/iron-sulfur protein β subunit = AcsC
Alternative forms of AcsCD corrinoid/iron-sulfur protein complex: corrinoid/iron-sulfur protein, methylated (extended summary available)
Summary:
The AcsCD corrinoid/iron-sulfur protein complex (C/Fe-SP) from Moorella thermoacetica acts as a methyl group carrier in the reductive acetyl coenzyme A pathway of CO and CO2 fixation. It is a dimer, consisting of a small (-33 kDa) and a large (-55 kDa) subunits, and contains 1 mol of cobalt in a corrinoid cofactor and 1 mol of [4Fe-4S] cluster per mol of an αβ dimer. The corrinoid cofactor was shown to be 5-methoxybenzimidazolylcobamide [Ljungdahl65]. Even though the cobamide binding sites are located in the small subunit, both subunits are required for formation of a stable cobamide-binding protein [Lu93a].
Prior to methylation the coblat must be in the highly reduced (I) state. During methylation the cobalt is oxidized to the (III) state, and is restored to the (I) state during demethylation. About once in 2000 reaction cycles the cobalt atom ends up in the (II) state, which is inactive. The inactive form can be reactivated by reduction of the cobalt to the (I) form. The [4Fe-4S] is involved in the reductive activation, and is able to transfer electrons from several sources, including reduced ferredoxins [Menon98].
The protein was first purified by Hu et al (1984). The genes encoding both subunits are located within a gene cluster that includes other genes required for CO2 fixation by anaerobic bacteria. The genes were cloned by [Roberts89] and eventually sequenced by [Lu93a], who also expressed it in Escherichia coli.
Citations: [Diekert94, Ljungdahl86, Ragsdale87 ]
Molecular Weight: 89 kD (experimental) [Hu84]
Gene-Reaction Schematic
Credits:
Revised 12-Dec-2011 by Caspi R, SRI International
Enzymatic reaction of: corrinoid/iron-sulfur protein |
2 carbon tetrachloride + an reduced unknown electron acceptor → 2 trichloromethyl radical + 2 chloride + an oxidized unknown electron acceptor + 2 H+
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.
The reaction is favored in the direction shown.
In Pathways: carbon tetrachloride degradation II
Summary:
This reaction is a non-specific, cometabolic reaction, in which the corrinoid protein catalyzes the reductive dechlorination of carbon tetrachloride to chloroform [Egli88]. The first part of the reaction is the generation of a radical [Krone91]. This radical may be protonated to form chloroform, or alternatively it could eliminate a chloride and become a dichlorocarbene [Krone91].
Enzymatic reaction of: chloroform dehalogenase (AcsCD corrinoid/iron-sulfur protein complex) |
chloroform + an reduced unknown electron acceptor → dichloromethane + chloride + an oxidized unknown electron acceptor + H+
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.
The reaction is favored in the direction shown.
In Pathways: carbon tetrachloride degradation I
Summary:
This reaction is a non-specific, cometabolic reaction, in which the corrinoid protein catalyzes the reductive dechlorination of chloroform to dichloromethane [Egli88].
Enzymatic reaction of: carbon tetrachloride dehalogenase (AcsCD corrinoid/iron-sulfur protein complex) |
carbon tetrachloride + an reduced unknown electron acceptor → chloroform + chloride + an oxidized unknown electron acceptor + H+
The direction shown, i.e. which substrates are on the left and right sides, is in accordance with the direction in which it was curated.
The reaction is favored in the direction shown.
In Pathways: carbon tetrachloride degradation I
Summary:
This reaction is a non-specific, cometabolic reaction, in which the corrinoid protein catalyzes the reductive dechlorination of carbon tetrachloride to chloroform [Egli88].
Subunit of AcsCD corrinoid/iron-sulfur protein complex: corrinoid/iron-sulfur protein α subunit
Synonyms: AcsD, corrinoid/Fe-S protein, α subunit, E[Co]-α subunit
| Gene: | acsD | Accession Number: G-3402 (MetaCyc) |
Molecular Weight: 33.0 kD (experimental) [Ragsdale87]
| Gene Class: | UNCLASSIFIED |
Unification Links: DIP:DIP-59670N, ModBase:Q07341, Protein Model Portal:Q07341, SMR:Q07341, Swiss-Model:Q07341, UniProt:Q07341
Relationship Links: InterPro:IN-FAMILY:IPR004486, InterPro:IN-FAMILY:IPR011005, InterPro:IN-FAMILY:IPR016041, PDB:Structure:4DJD, PDB:Structure:4DJE, PDB:Structure:4DJF, Pfam:IN-FAMILY:PF03599
Subunit of AcsCD corrinoid/iron-sulfur protein complex: corrinoid/iron-sulfur protein β subunit
Synonyms: AcsC, corrinoid/Fe-S protein β subunit, E[Co]-β subunit
| Gene: | acsC | Accession Number: G-3403 (MetaCyc) |
Molecular Weight: 55.0 kD (experimental) [Ragsdale87]
| Gene Class: | UNCLASSIFIED |
Unification Links: DIP:DIP-59669N, ModBase:Q07340, Protein Model Portal:Q07340, SMR:Q07340, Swiss-Model:Q07340, UniProt:Q07340
Relationship Links: InterPro:IN-FAMILY:IPR007202, InterPro:IN-FAMILY:IPR011005, InterPro:IN-FAMILY:IPR016041, InterPro:IN-FAMILY:IPR016218, PDB:Structure:4DJD, PDB:Structure:4DJE, PDB:Structure:4DJF, Pfam:IN-FAMILY:PF03599, Pfam:IN-FAMILY:PF04060, Prosite:IN-FAMILY:PS51656
References
Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by Pathway Tools version 19.5 (software by SRI International) on Sat Jul 13, 2024.
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