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9  structures 3288  species 0  interactions 4229  sequences 28  architectures

# Summary: Magnesium chelatase, subunit ChlI

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

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

# Magnesium chelatase

magnesium chelatase
Identifiers
EC number 6.6.1.1
CAS number 9074-88-8
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Gene Ontology AmiGO / EGO
Magnesium chelatase, ChlI subunit
Identifiers
Symbol Mg_chelatse_chII
Pfam PF01078
InterPro IPR000523
CobN/magnesium chelatase
Identifiers
Symbol CobN/Mg_chltase
Pfam PF02514
InterPro IPR003672

Magnesium-chelatase is a three-component enzyme that catalyses the insertion of Mg2+ into protoporphyrin IX. This is the first unique step in the synthesis of bacteriochlorophyll. As a result, it is thought that Mg-chelatase has an important role in channeling intermediates into the (bacterio)chlorophyll branch in response to conditions suitable for photosynthetic growth:

ATP + protoporphyrin IX + Mg2+ + H2O $\rightleftharpoons$ 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.

## References

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.

# Magnesium chelatase, subunit ChlI

Magnesium-chelatase is a three-component enzyme that catalyses the insertion of Mg2+ into protoporphyrin IX. This is the first unique step in the synthesis of (bacterio)chlorophyll. Due to this, it is thought that Mg-chelatase has an important role in channelling inter- mediates into the (bacterio)chlorophyll branch in response to conditions suitable for photosynthetic growth. ChlI and BchD have molecular weight between 38-42 kDa.

## Literature references

1. Walker CJ, Willows RD; , Biochem J 1997;327:321-333.: Mechanism and regulation of Mg-chelatase. PUBMED:9359397 EPMC:9359397

2. Petersen BL, Jensen PE, Gibson LC, Stummann BM, Hunter CN, Henningsen KW; , J Bacteriol 1998;180:699-704.: Reconstitution of an active magnesium chelatase enzyme complex from the bchI, -D, and -H gene products of the green sulfur bacterium Chlorobium vibrioforme expressed in Escherichia coli. PUBMED:9457877 EPMC:9457877

This tab holds annotation information from the InterPro database.

# InterPro entry IPR000523

Magnesium-chelatase is a three-component enzyme that catalyses the insertion of Mg2+ into protoporphyrin IX. This is the first unique step in the synthesis of (bacterio)chlorophyll. As a result, it is thought that Mg-chelatase has an important role in channeling intermediates into the (bacterio)chlorophyll branch in response to conditions suitable for photosynthetic growth. ChlI and BchD have molecular weights between 38-42 kDa.

### Gene Ontology

The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.

# Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

# Alignments

We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...

## View options

We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.

Seed
(56)
Full
(4229)
Representative proteomes NCBI
(9364)
Meta
(2476)
RP15
(414)
RP35
(845)
RP55
(1059)
RP75
(1225)
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PP/heatmap 1 View  View  View  View  View
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: available, not generated, not available.

## Format an alignment

Seed
(56)
Full
(4229)
Representative proteomes NCBI
(9364)
Meta
(2476)
RP15
(414)
RP35
(845)
RP55
(1059)
RP75
(1225)
Alignment:
Format:
Order:
Sequence:
Gaps:

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

Seed
(56)
Full
(4229)
Representative proteomes NCBI
(9364)
Meta
(2476)
RP15
(414)
RP35
(845)
RP55
(1059)
RP75
(1225)

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

# HMM logo

HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...

# Trees

This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

# Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

## Curation

 Seed source: Pfam-B_616 (release 3.0) Previous IDs: none Type: Family Author: Finn RD, Bateman A Number in seed: 56 Number in full: 4229 Average length of the domain: 172.30 aa Average identity of full alignment: 42 % Average coverage of the sequence by the domain: 36.05 %

## HMM information

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 20.3 20.3
Trusted cut-off 20.3 20.3
Noise cut-off 20.2 20.2
Model length: 207
Family (HMM) version: 16

# Species distribution

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