2fr5
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:2fr5.gif|left|200px]] | [[Image:2fr5.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_2fr5", 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_2fr5| PDB=2fr5 | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''Crystal Structure of Mouse Cytidine Deaminase Complexed with Tetrahydrouridine''' | '''Crystal Structure of Mouse Cytidine Deaminase Complexed with Tetrahydrouridine''' | ||
| Line 27: | Line 24: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Teh, A H.]] | [[Category: Teh, A H.]] | ||
| - | [[Category: | + | [[Category: Alternate conformation of arg68]] |
| - | [[Category: | + | [[Category: Cytidine deaminase]] |
| - | [[Category: | + | [[Category: Protein-inhibitor complex]] |
| - | [[Category: | + | [[Category: Tetrahydrouridine]] |
| - | [[Category: | + | [[Category: Zinc]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 04:13:10 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 01:13, 4 May 2008
Crystal Structure of Mouse Cytidine Deaminase Complexed with Tetrahydrouridine
Overview
Cytidine deaminase (CDA) is a zinc-dependent enzyme that catalyzes the deamination of cytidine or deoxycytidine to form uridine or deoxyuridine. Here we present the crystal structure of mouse CDA (MmCDA), complexed with either tetrahydrouridine (THU), 3-deazauridine (DAU), or cytidine. In the MmCDA-DAU complex, it clearly demonstrates that cytidine is distinguished from uridine by its 4-NH(2) group that acts as a hydrogen bond donor. In the MmCDA-cytidine complex, cytidine, unexpectedly, binds as the substrate instead of the deaminated product in three of the four subunits, and in the remaining subunit it binds as the product uridine. Furthermore, the charge-neutralizing Arg68 of MmCDA has also exhibited two alternate conformations, I and II. In conformation I, the only conformation observed in the other structurally known homotetrameric CDAs, Arg68 hydrogen bonds Cys65 and Cys102 to modulate part of their negative charges. However, in conformation II the side chain of Arg68 rotates about 130 degrees around the Cgamma-Cdelta bond and abolishes these hydrogen bonds. The lack of hydrogen bonding may indirectly weaken the zinc-product interaction by increased electron donation from cysteine to the zinc ion, suggesting a novel product-expelling mechanism. On the basis of known structures, structural analysis further reveals two subclasses of homotetrameric CDAs that can be identified according to the position of the charge-neutralizing arginine residue. Implications for CDA-RNA interaction have also been considered.
About this Structure
2FR5 is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
The 1.48 A resolution crystal structure of the homotetrameric cytidine deaminase from mouse., Teh AH, Kimura M, Yamamoto M, Tanaka N, Yamaguchi I, Kumasaka T, Biochemistry. 2006 Jun 27;45(25):7825-33. PMID:16784234 Page seeded by OCA on Sun May 4 04:13:10 2008
