3faq

Crystal structure of lactoperoxidase complex with cyanide

spinqualitylabelsall models 3faq, resolution 2.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3faq is a 1 chain structure with sequence from Bubalus bubalis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.7Å Ligands: BMA, CA, CYN, HEM, IOD, MAN, NAG, SCN, SEP Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PERL_BUBBU Antimicrobial agent which utilizes hydrogen peroxide and thiocyanate (SCN) to generate the antimicrobial substance hypothiocyanous acid (HOSCN). May protect the udder from infection and promote growth in newborn calves. Inhibits growth of the following bacterial species: E.coli, K.pneumoniae, P.aeruginosa, S.sonnei, S.saphrophyticus, S.epidermidis, and S.dysenteriae. 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 PubMed The crystal structure of the complex of lactoperoxidase (LPO) with its physiological substrate thiocyanate (SCN(-)) has been determined at 2.4A resolution. It revealed that the SCN(-) ion is bound to LPO in the distal heme cavity. The observed orientation of the SCN(-) ion shows that the sulfur atom is closer to the heme iron than the nitrogen atom. The nitrogen atom of SCN(-) forms a hydrogen bond with a water (Wat) molecule at position 6'. This water molecule is stabilized by two hydrogen bonds with Gln(423) N(epsilon2) and Phe(422) oxygen. In contrast, the placement of the SCN(-) ion in the structure of myeloperoxidase (MPO) occurs with an opposite orientation, in which the nitrogen atom is closer to the heme iron than the sulfur atom. The site corresponding to the positions of Gln(423), Phe(422) oxygen, and Wat(6)' in LPO is occupied primarily by the side chain of Phe(407) in MPO due to an entirely different conformation of the loop corresponding to the segment Arg(418)-Phe(431) of LPO. This arrangement in MPO does not favor a similar orientation of the SCN(-) ion. The orientation of the catalytic product OSCN(-) as reported in the structure of LPO.OSCN(-) is similar to the orientation of SCN(-) in the structure of LPO.SCN(-). Similarly, in the structure of LPO.SCN(-).CN(-), in which CN(-) binds at Wat(1), the position and orientation of the SCN(-) ion are also identical to that observed in the structure of LPO.SCN. Structural evidence of substrate specificity in mammalian peroxidases: structure of the thiocyanate complex with lactoperoxidase and its interactions at 2.4 A resolution.,Sheikh IA, Singh AK, Singh N, Sinha M, Singh SB, Bhushan A, Kaur P, Srinivasan A, Sharma S, Singh TP J Biol Chem. 2009 May 29;284(22):14849-56. Epub 2009 Apr 1. PMID:19339248 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Lactoperoxidase

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