1im8

From Proteopedia

---

Revision as of 15:22, 20 November 2007

proteopedia linkproteopedia link

spinqualitylabelsall models 1im8, resolution 2.2Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of YecO from Haemophilus influenzae (HI0319), a methyltransferase with a bound S-adenosylhomocysteine

Overview

The crystal structure of YecO from Haemophilus influenzae (HI0319), a, protein annotated in the sequence databases as hypothetical, and that has, not been assigned a function, has been determined at 2.2-A resolution. The, structure reveals a fold typical of S-adenosyl-L-methionine-dependent, (AdoMet) methyltransferase enzymes. Moreover, a processed cofactor, S-adenosyl-L-homocysteine (AdoHcy), is bound to the enzyme, further, confirming the biochemical function of HI0319 and its sequence family, members. An active site arginine, shielded from bulk solvent, interacts, with an anion, possibly a chloride ion, which in turn interacts with the, sulfur atom of AdoHcy. The AdoHcy and nearby protein residues delineate a, small solvent-excluded substrate binding cavity of 162 A(3) in volume. The, environment surrounding the cavity indicates that the substrate molecule, contains a hydrophobic moiety and an anionic group. Many of the residues, that define the cavity are invariant in the HI0319 sequence family but are, not conserved in other methyltransferases. Therefore, the substrate, specificity of YecO enzymes is unique and differs from the substrate, specificity of all other methyltransferases sequenced to date. Examination, of the Enzyme Commission list of methyltransferases prompted a manual, inspection of 10 possible substrates using computer graphics and suggested, that the ortho-substituted benzoic acids fit best in the active site.

About this Structure

1IM8 is a Single protein structure of sequence from Haemophilus influenzae with CL and SAI as ligands. Full crystallographic information is available from OCA.

Reference

Crystal structure of YecO from Haemophilus influenzae (HI0319) reveals a methyltransferase fold and a bound S-adenosylhomocysteine., Lim K, Zhang H, Tempczyk A, Bonander N, Toedt J, Howard A, Eisenstein E, Herzberg O, Proteins. 2001 Dec 1;45(4):397-407. PMID:11746687

Page seeded by OCA on Tue Nov 20 17:30:08 2007