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17  structures 2645  species 0  interactions 4985  sequences 32  architectures

Family: CobN-Mg_chel (PF02514)

Summary: CobN/Magnesium Chelatase

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This is the Wikipedia entry entitled "Magnesium chelatase". More...

Magnesium chelatase Edit Wikipedia article

In enzymology, a magnesium chelatase (EC is an enzyme that catalyzes the chemical reaction

ATP + protoporphyrin IX + Mg2+ + H2O ADP + phosphate + Mg-protoporphyrin IX + 2 H+

The 4 substrates of this enzyme are ATP, protoporphyrin IX, Mg2+, and H2O, whereas its 4 products are ADP, phosphate, Mg-protoporphyrin IX, and H+.

This enzyme belongs to the family of ligases, specifically those forming nitrogen-D-metal bonds in coordination complexes. The systematic name of this enzyme class is Mg-protoporphyrin IX magnesium-lyase. Other names in common use include protoporphyrin IX magnesium-chelatase, protoporphyrin IX Mg-chelatase, magnesium-protoporphyrin IX chelatase, magnesium-protoporphyrin chelatase, magnesium-chelatase, Mg-chelatase, and Mg-protoporphyrin IX magnesio-lyase. This enzyme participates in porphyrin and chlorophyll metabolism.


Template:Enzyme references

  • Walker CJ, Weinstein JD (1991). "In vitro assay of the chlorophyll biosynthetic enzyme Mg-chelatase: resolution of the activity into soluble and membrane-bound fractions". Proc. Natl. Acad. Sci. U. S. A. 88: 5789–93. PMID 11607197.
  • Walker CJ, Willows RD (Pt 2). "Mechanism and regulation of Mg-chelatase". Biochem. J. 327: 321–33. PMID 9359397. {{cite journal}}: Check date values in: |date= (help)
  • Al-Karadaghi S (2001). "Interplay between an AAA module and an integrin I domain may regulate the function of magnesium chelatase". J. Mol. Biol. 311: 111–22. PMID 11469861.

External links

The CAS registry number for this enzyme class is Template:CAS registry.

Template:Enzyme links

Gene Ontology (GO) codes

Template:GO code links

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

CobN/Magnesium Chelatase Provide feedback

This family contains a domain common to the cobN protein and to magnesium protoporphyrin chelatase. CobN is implicated in the conversion of hydrogenobyrinic acid a,c-diamide to cobyrinic acid [1]. Magnesium protoporphyrin chelatase is involved in chlorophyll biosynthesis [2].

Literature references

  1. Crouzet J, Levy-Schil S, Cameron B, Cauchois L, Rigault S, Rouyez MC, Blanche F, Debussche L, Thibaut D; , J Bacteriol 1991;173:6074-6087.: Nucleotide sequence and genetic analysis of a 13.1-kilobase-pair Pseudomonas denitrificans DNA fragment containing five cob genes and identification of structural genes encoding Cob(I)alamin adenosyltransferase, cobyric acid synthase, and bifunctional cob PUBMED:1655697 EPMC:1655697

  2. Hudson A, Carpenter R, Doyle S, Coen ES; , EMBO J 1993;12:3711-3719.: Olive: a key gene required for chlorophyll biosynthesis in Antirrhinum majus. PUBMED:8404842 EPMC:8404842

This tab holds annotation information from the InterPro database.

InterPro entry IPR003672

This family contains a domain common to the cobN protein and to magnesium protoporphyrin chelatase. CobN may play a role in cobalt insertion reactions and is implicated in the conversion of precorrin-2 to cobyrinic acid in cobalamin biosynthesis [ PUBMED:1655697 ]. Magnesium protoporphyrin chelatase is involved in chlorophyll biosynthesis as the third subunit of light-independent protochlorophyllide reductase in bacteria and plants [ PUBMED:8385667 ].

Gene Ontology

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Domain organisation

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Curation and family details

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Seed source: Pfam-B_647 (release 5.4)
Previous IDs: cobN-Mg_chel;
Type: Family
Sequence Ontology: SO:0100021
Author: Mian N , Bateman A , Griffiths-Jones SR
Number in seed: 339
Number in full: 4985
Average length of the domain: 815.7 aa
Average identity of full alignment: 29 %
Average coverage of the sequence by the domain: 85.57 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null --hand HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 24.5 24.5
Trusted cut-off 25.3 25.4
Noise cut-off 24.1 24.4
Model length: 1092
Family (HMM) version: 19
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Species distribution

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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 CobN-Mg_chel domain has been found. There are 17 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 sequence.

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