1e85 | pdb_00001e85
CYTOCHROME C' FROM ALCALIGENES XYLOSOXIDANS-REDUCED STRUCTURE WITH NO BOUND TO PROXIMAL SIDE OF HEME
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| 1e85, resolution 1.35Å | |||||||||||||
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| Sites: | HEC and NMO | ||||||||||||
| Ligands: | HEC and NO | ||||||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||||||
Overview
Microbial cytochromes c' contain a 5-coordinate His-ligated heme that forms stable adducts with nitric oxide (NO) and carbon monoxide (CO), but not with dioxygen. We report the 1.95 and 1.35 A resolution crystal structures of the CO- and NO-bound forms of the reduced protein from Alcaligenes xylosoxidans. NO disrupts the His-Fe bond and binds in a novel mode to the proximal face of the heme, giving a 5-coordinate species. In contrast, CO binds 6-coordinate on the distal side. A second CO molecule, not bound to the heme, is located in the proximal pocket. Since the unusual spectroscopic properties of cytochromes c' are shared by soluble guanylate cyclase (sGC), our findings have potential implications for the activation of sGC induced by the binding of NO or CO to the heme domain.
About this Structure
1E85 is a Single protein structure of sequence from Achromobacter xylosoxidans. Full crystallographic information is available from OCA.
Reference
Unprecedented proximal binding of nitric oxide to heme: implications for guanylate cyclase., Lawson DM, Stevenson CE, Andrew CR, Eady RR, EMBO J. 2000 Nov 1;19(21):5661-71. PMID:11060017
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