1cqx
Crystal structure of the flavohemoglobin from Alcaligenes eutrophus at 1.75 A resolution
Structural highlights
FunctionHMP_CUPNH Is involved in NO detoxification in an aerobic process, termed nitric oxide dioxygenase (NOD) reaction that utilizes O(2) and NAD(P)H to convert NO to nitrate, which protects the bacterium from various noxious nitrogen compounds. Therefore, plays a central role in the inducible response to nitrosative stress. In the presence of oxygen and NADH, FHP has NADH oxidase activity, which leads to the generation of superoxide and H(2)O(2), both in vitro and in vivo, and it has been suggested that FHP might act as an amplifier of superoxide stress. Under anaerobic conditions, FHP also exhibits nitric oxide reductase and FAD reductase activities. However, all these reactions are much lower than NOD activity. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe molecular structure of the flavohemoglobin from Alcaligenes eutrophus has been determined to a resolution of 1.75 A and refined to an R-factor of 19.6%. The protein comprises two fused modules: a heme binding module, which belongs to the globin family, and an FAD binding oxidoreductase module, which adopts a fold like ferredoxin reductase. The most striking deviation of the bacterial globin structure from those of other species is the movement of helix E in a way to provide more space in the vicinity of the distal heme binding site. A comparison with other members of the ferredoxin reductase family shows similar tertiary structures for the individual FAD and NAD binding domains but largely different interdomain orientations. The heme and FAD molecules approach each other to a minimal distance of 6.3 A and adopt an interplanar angle of 80 degrees. The electron transfer from FAD to heme occurs in a predominantly polar environment and may occur directly or be mediated by a water molecule. Crystal structure of the flavohemoglobin from Alcaligenes eutrophus at 1.75 A resolution.,Ermler U, Siddiqui RA, Cramm R, Friedrich B EMBO J. 1995 Dec 15;14(24):6067-77. PMID:8557026[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences | ||||||||||||||||||||
