5js5

Nitric oxide complex of the L16F mutant of cytochrome c prime from Alcaligenes xylosoxidans

spinqualitylabelsall models 5js5, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5js5 is a 1 chain structure with sequence from Achromobacter xylosoxidans. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.7Å Ligands: ASC, HEC, NO, PCA Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CYCP_ALCXX Cytochrome c' is the most widely occurring bacterial c-type cytochrome. Cytochromes c' are high-spin proteins and the heme has no sixth ligand. Their exact function is not known. Publication Abstract from PubMed Proximal vs. distal heme-NO coordination is a novel strategy for selective gas response in heme-based NO-sensors. In the case of Alcaligenes xylosoxidans cytochrome c' (AXCP), formation of a transient distal 6cNO complex is followed by scission of the trans Fe-His bond and conversion to a proximal 5cNO product via a putative dinitrosyl species. Here we show that replacement of the AXCP distal Leu16 residue with smaller or similar sized residues (Ala, Val or Ile) traps the distal 6cNO complex, whereas Leu or Phe residues lead to a proximal 5cNO product with a transient or non-detectable distal 6cNO precursor. Crystallographic, spectroscopic, and kinetic measurements of 6cNO AXCP complexes show that increased distal steric hindrance leads to distortion of the Fe-N-O angle and flipping of the heme 7-propionate. However, it is the kinetic parameters of the distal NO ligand that determine whether 6cNO or proximal 5cNO end products are formed. Our data support a 'balance of affinities' mechanism in which proximal 5cNO coordination depends on relatively rapid release of the distal NO from the dinitrosyl precursor. This mechanism, which is applicable to other proteins that form transient dinitrosyls, represents a novel strategy for 5cNO formation that does not rely on an inherently weak Fe-His bond. Our data suggest a general means of engineering selective gas response into biologically-derived gas sensors in synthetic biology. Engineering proximal vs. distal heme-NO coordination via dinitrosyl dynamics: implications for NO sensor design.,Kekilli D, Petersen CA, Pixton DA, Ghafoor DD, Abdullah GH, Dworkowski FSN, Wilson MT, Heyes DJ, Hardman SJO, Murphy LM, Strange RW, Scrutton NS, Andrew CR, Hough MA Chem Sci. 2017 Mar 1;8(3):1986-1994. doi: 10.1039/c6sc04190f. Epub 2016 Nov 16. PMID:28451315 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Cytochrome C 3D structures

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