1ehb
CRYSTAL STRUCTURE OF RECOMBINANT TRYPSIN-SOLUBILIZED FRAGMENT OF CYTOCHROME B5
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OverviewOverview
The crystal structure of the recombinant trypsin-solubilized fragment of, the microsomal cytochrome b(5) from bovine liver has been determined at, 1.9 A resolution and compared with the reported crystal structure of the, lipase-solubilized fragment of the membrane protein cytochrome b(5). The, two structures are similar to each other. However, some detailed, structural differences are observed: the conformation of the segment, Asn16-Ser20 is quite different, some helices around the heme and some, segments between the helices are shifted slightly, the heme is rotated, about the normal of the mean plane of heme, one of the propionates of the, heme exhibits a different conformation. The average coordination distances, between the iron and the two nitrogen atoms of the imidazole ligands are, the same in the two structures. Most of the structural differences can be, attributed to the different intermolecular interactions which result from, the crystal packing. The wild-type protein structure is also compared with, its Val61His mutant, showing that the heme binding and the main chain, conformations are basically identical with each other except for the local, area of the mutation site. However, when Val61 is mutated to histidine, the large side chain of His61 is forced to point away from the heme pocket, toward the solvent region, disturbing the micro-environment of the heme, pocket and influencing the stability and the redox potential of the, protein.
About this StructureAbout this Structure
1EHB is a Single protein structure of sequence from Bos taurus with HEM as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of recombinant trypsin-solubilized fragment of cytochrome b(5) and the structural comparison with Val61His mutant., Wu J, Gan JH, Xia ZX, Wang YH, Wang WH, Xue LL, Xie Y, Huang ZX, Proteins. 2000 Aug 1;40(2):249-57. PMID:10842340
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