1E84

Cytochrome c' from Alcaligenes xylosoxidans - reduced structure

Summary for 1E84

• Entry DOI: 10.2210/pdb1e84/pdb
• Related: 1CGO 1E83 1E85 1E86
• Descriptor: CYTOCHROME C', HEME C (3 entities in total)
• Functional Keywords: cytochrome, heme, 4-helix bundle, electron transport
• Biological source: ALCALIGENES XYLOSOXIDANS
• Total number of polymer chains: 1
• Total formula weight: 14249.94

Authors

Lawson, D.M.,Stevenson, C.E.M.,Andrew, C.R.,Eady, R.R. (deposition date: 2000-09-15, release date: 2000-11-06, Last modification date: 2024-10-16)

Primary citation

Lawson, D.M.,Stevenson, C.E.M.,Andrew, C.R.,Eady, R.R.
Unprecedented Proximal Binding of Nitric Oxide to Heme: Implications for Guanylate Cyclase
Embo J., 19:5661-, 2000

PubMed Abstract: 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.

PubMed: 11060017
DOI: 10.1093/EMBOJ/19.21.5661

Experimental method

X-RAY DIFFRACTION (1.9 Å)