2bi7: Difference between revisions
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==Overview== | ==Overview== | ||
Uridine diphosphogalactofuranose (UDP-Galf) is the precursor of the, d-galactofuranose sugar found in bacterial and parasitic cell walls, including those of many pathogens. UDP-Galf is made from, UDP-galactopyranose by the enzyme UDP-galactopyranose mutase. The enzyme, requires the reduced FADH- co-factor for activity. The structure of the, Mycobacterium tuberculosis mutase with FAD has been determined to 2.25 A., The structures of Klebsiella pneumoniae mutase with FAD and with FADH-, bound have been determined to 2.2 A and 2.35 A resolution, respectively., This is the first report of the FADH(-)-containing structure. Two, flavin-dependent mechanisms for the enzyme have been proposed, one, which, involves a covalent adduct being formed at the flavin and the other based, on electron ... | Uridine diphosphogalactofuranose (UDP-Galf) is the precursor of the, d-galactofuranose sugar found in bacterial and parasitic cell walls, including those of many pathogens. UDP-Galf is made from, UDP-galactopyranose by the enzyme UDP-galactopyranose mutase. The enzyme, requires the reduced FADH- co-factor for activity. The structure of the, Mycobacterium tuberculosis mutase with FAD has been determined to 2.25 A., The structures of Klebsiella pneumoniae mutase with FAD and with FADH-, bound have been determined to 2.2 A and 2.35 A resolution, respectively., This is the first report of the FADH(-)-containing structure. Two, flavin-dependent mechanisms for the enzyme have been proposed, one, which, involves a covalent adduct being formed at the flavin and the other based, on electron transfer. Using our structural data, we have examined the two, mechanisms. The electron transfer mechanism is consistent with the, structural data, not surprisingly, since it makes fewer demands on the, precise positioning of atoms. A model based on a covalent adduct FAD, requires repositioning of the enzyme active site and would appear to, require the isoalloxazine ring of FADH- to buckle in a particular way., However, the FADH- structure reveals that the isoalloxazine ring buckles, in the opposite sense, this apparently requires the covalent adduct to, trigger profound conformational changes in the protein or to buckle the, FADH- opposite to that seen in the apo structure. | ||
==About this Structure== | ==About this Structure== | ||
2BI7 is a | 2BI7 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Klebsiella_pneumoniae Klebsiella pneumoniae] with FAD as [http://en.wikipedia.org/wiki/ligand ligand]. This structure superseeds the now removed PDB entry 1USJ. Active as [http://en.wikipedia.org/wiki/UDP-galactopyranose_mutase UDP-galactopyranose mutase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.4.99.9 5.4.99.9] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BI7 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: lipopolysaccharide biosynthesis]] | [[Category: lipopolysaccharide biosynthesis]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 15:22:04 2007'' | ||
Revision as of 16:16, 5 November 2007
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UDP-GALACTOPYRANOSE MUTASE FROM KLEBSIELLA PNEUMONIAE OXIDISED FAD
OverviewOverview
Uridine diphosphogalactofuranose (UDP-Galf) is the precursor of the, d-galactofuranose sugar found in bacterial and parasitic cell walls, including those of many pathogens. UDP-Galf is made from, UDP-galactopyranose by the enzyme UDP-galactopyranose mutase. The enzyme, requires the reduced FADH- co-factor for activity. The structure of the, Mycobacterium tuberculosis mutase with FAD has been determined to 2.25 A., The structures of Klebsiella pneumoniae mutase with FAD and with FADH-, bound have been determined to 2.2 A and 2.35 A resolution, respectively., This is the first report of the FADH(-)-containing structure. Two, flavin-dependent mechanisms for the enzyme have been proposed, one, which, involves a covalent adduct being formed at the flavin and the other based, on electron transfer. Using our structural data, we have examined the two, mechanisms. The electron transfer mechanism is consistent with the, structural data, not surprisingly, since it makes fewer demands on the, precise positioning of atoms. A model based on a covalent adduct FAD, requires repositioning of the enzyme active site and would appear to, require the isoalloxazine ring of FADH- to buckle in a particular way., However, the FADH- structure reveals that the isoalloxazine ring buckles, in the opposite sense, this apparently requires the covalent adduct to, trigger profound conformational changes in the protein or to buckle the, FADH- opposite to that seen in the apo structure.
About this StructureAbout this Structure
2BI7 is a Single protein structure of sequence from Klebsiella pneumoniae with FAD as ligand. This structure superseeds the now removed PDB entry 1USJ. Active as UDP-galactopyranose mutase, with EC number 5.4.99.9 Structure known Active Site: AC1. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structures of Mycobacteria tuberculosis and Klebsiella pneumoniae UDP-galactopyranose mutase in the oxidised state and Klebsiella pneumoniae UDP-galactopyranose mutase in the (active) reduced state., Beis K, Srikannathasan V, Liu H, Fullerton SW, Bamford VA, Sanders DA, Whitfield C, McNeil MR, Naismith JH, J Mol Biol. 2005 May 13;348(4):971-82. PMID:15843027
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