1c0n
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1c0n.gif|left|200px]] | [[Image:1c0n.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1c0n", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | | | + | or leave the SCENE parameter empty for the default display. |
| - | | | + | --> |
| - | + | {{STRUCTURE_1c0n| PDB=1c0n | SCENE= }} | |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''CSDB PROTEIN, NIFS HOMOLOGUE''' | '''CSDB PROTEIN, NIFS HOMOLOGUE''' | ||
| Line 31: | Line 28: | ||
[[Category: Maeda, M.]] | [[Category: Maeda, M.]] | ||
[[Category: Mihara, H.]] | [[Category: Mihara, H.]] | ||
| - | [[Category: | + | [[Category: Alpha/beta fold]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 12:11:39 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 09:11, 2 May 2008
CSDB PROTEIN, NIFS HOMOLOGUE
Overview
Escherichia coli CsdB, a NifS homologue with a high specificity for L-selenocysteine, is a pyridoxal 5'-phosphate (PLP)-dependent dimeric enzyme that belongs to aminotransferases class V in fold-type I of PLP enzymes and catalyzes the decomposition of L-selenocysteine into selenium and L-alanine. The crystal structure of the enzyme has been determined by the X-ray crystallographic method of multiple isomorphous replacement and refined to an R-factor of 18.7% at 2.8 A resolution. The subunit structure consists of three parts: a large domain of an alpha/beta-fold containing a seven-stranded beta-sheet flanked by seven helices, a small domain containing a four-stranded antiparallel beta-sheet flanked by three alpha-helices, and an N-terminal segment containing two alpha-helices. The overall fold of the subunit is similar to those of the enzymes belonging to the fold-type I family represented by aspartate aminotransferase. However, CsdB has several structural features that are not observed in other families of the enzymes. A remarkable feature is that an alpha-helix in the lobe extending from the small domain to the large domain in one subunit of the dimer interacts with a beta-hairpin loop protruding from the large domain of the other subunit. The extended lobe and the protruded beta-hairpin loop form one side of a limb of each active site in the enzyme. The most striking structural feature of CsdB lies in the location of a putative catalytic residue; the side chain of Cys364 on the extended lobe of one subunit is close enough to interact with the gamma-atom of a modeled substrate in the active site of the subunit. Moreover, His55 from the other subunit is positioned so that it interacts with the gamma- or beta-atom of the substrate and may be involved in the catalytic reaction. This is the first report on three-dimensional structures of NifS homologues.
About this Structure
1C0N is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Structure of a NifS homologue: X-ray structure analysis of CsdB, an Escherichia coli counterpart of mammalian selenocysteine lyase., Fujii T, Maeda M, Mihara H, Kurihara T, Esaki N, Hata Y, Biochemistry. 2000 Feb 15;39(6):1263-73. PMID:10684605 Page seeded by OCA on Fri May 2 12:11:39 2008
