1g8p
From Proteopedia
| Line 7: | Line 7: | ||
|ACTIVITY= | |ACTIVITY= | ||
|GENE= BCHI_RHOCA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1061 Rhodobacter capsulatus]) | |GENE= BCHI_RHOCA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1061 Rhodobacter capsulatus]) | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY= | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1g8p FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1g8p OCA], [http://www.ebi.ac.uk/pdbsum/1g8p PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1g8p RCSB]</span> | ||
}} | }} | ||
| Line 34: | Line 37: | ||
[[Category: rossman fold]] | [[Category: rossman fold]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 20:38:57 2008'' |
Revision as of 17:39, 30 March 2008
| |||||||
| , resolution 2.10Å | |||||||
|---|---|---|---|---|---|---|---|
| Gene: | BCHI_RHOCA (Rhodobacter capsulatus) | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
CRYSTAL STRUCTURE OF BCHI SUBUNIT OF MAGNESIUM CHELATASE
Overview
In chlorophyll biosynthesis, insertion of Mg(2+) into protoporphyrin IX is catalysed in an ATP-dependent reaction by a three-subunit (BchI, BchD and BchH) enzyme magnesium chelatase. In this work we present the three-dimensional structure of the ATP-binding subunit BchI. The structure has been solved by the multiple wavelength anomalous dispersion method and refined at 2.1 A resolution to the crystallographic R-factor of 22.2 % (R(free)=24.5 %). It belongs to the chaperone-like "ATPase associated with a variety of cellular activities" (AAA) family of ATPases, with a novel arrangement of domains: the C-terminal helical domain is located behind the nucleotide-binding site, while in other known AAA module structures it is located on the top. Examination by electron microscopy of BchI solutions in the presence of ATP demonstrated that BchI, like other AAA proteins, forms oligomeric ring structures. Analysis of the amino acid sequence of subunit BchD revealed an AAA module at the N-terminal portion of the sequence and an integrin I domain at the C terminus. An acidic, proline-rich region linking these two domains is suggested to contribute to the association of BchI and BchD by binding to a positively charged cleft at the surface of the nucleotide-binding domain of BchI. Analysis of the amino acid sequences of BchI and BchH revealed integrin I domain-binding sequence motifs. These are proposed to bind the integrin I domain of BchD during the functional cycle of magnesium chelatase, linking porphyrin metallation by BchH to ATP hydrolysis by BchI. An integrin I domain and an acidic and proline-rich region have been identified in subunit CobT of cobalt chelatase, clearly demonstrating its homology to BchD. These findings, for the first time, provide an insight into the subunit organisation of magnesium chelatase and the homologous colbalt chelatase.
About this Structure
1G8P is a Single protein structure of sequence from Rhodobacter capsulatus. Full crystallographic information is available from OCA.
Reference
Interplay between an AAA module and an integrin I domain may regulate the function of magnesium chelatase., Fodje MN, Hansson A, Hansson M, Olsen JG, Gough S, Willows RD, Al-Karadaghi S, J Mol Biol. 2001 Aug 3;311(1):111-22. PMID:11469861
Page seeded by OCA on Sun Mar 30 20:38:57 2008
