1ig8
From Proteopedia
Crystal Structure of Yeast Hexokinase PII with the correct amino acid sequence
Overview
Hexokinase is the first enzyme in the glycolytic pathway, catalyzing the transfer of a phosphoryl group from ATP to glucose to form glucose 6-phosphate and ADP. Two yeast hexokinase isozymes are known, namely PI and PII. The crystal structure of yeast hexokinase PII from Saccharomyces cerevisiae without substrate or competitive inhibitor is determined and refined in a tetragonal crystal form at 2.2-A resolution. The folding of the peptide chain is very similar to that of Schistosoma mansoni and previous yeast hexokinase models despite only 30% sequence identity between them. Distinct differences in conformation are found that account for the absence of glucose in the binding site. Comparison of the current model with S. mansoni and yeast hexokinase PI structures both complexed with glucose shows in atomic detail the rigid body domain closure and specific loop movements as glucose binds. A hydrophobic channel formed by strictly conserved hydrophobic residues in the small domain of the hexokinase is identified. The channel's mouth is close to the active site and passes through the small domain to its surface. The possible role of the observed channel in proton transfer is discussed.
About this Structure
1IG8 is a Single protein structure of sequence from Saccharomyces cerevisiae. The following page contains interesting information on the relation of 1IG8 with [The Glycolytic Enzymes]. Full crystallographic information is available from OCA.
Reference
The high resolution crystal structure of yeast hexokinase PII with the correct primary sequence provides new insights into its mechanism of action., Kuser PR, Krauchenco S, Antunes OA, Polikarpov I, J Biol Chem. 2000 Jul 7;275(27):20814-21. PMID:10749890 Page seeded by OCA on Fri May 2 19:57:59 2008
