2e1q
From Proteopedia
(New page: 200px<br /> <applet load="2e1q" size="450" color="white" frame="true" align="right" spinBox="true" caption="2e1q, resolution 2.6Å" /> '''Crystal Structure of...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:2e1q. | + | [[Image:2e1q.jpg|left|200px]]<br /><applet load="2e1q" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="2e1q" size=" | + | |
caption="2e1q, resolution 2.6Å" /> | caption="2e1q, resolution 2.6Å" /> | ||
'''Crystal Structure of Human Xanthine Oxidoreductase mutant, Glu803Val'''<br /> | '''Crystal Structure of Human Xanthine Oxidoreductase mutant, Glu803Val'''<br /> | ||
| Line 6: | Line 5: | ||
==Overview== | ==Overview== | ||
Xanthine oxidase (oxidoreductase; XOR) and aldehyde oxidase (AO) are, similar in protein structure and prosthetic group composition, but differ, in substrate preference. Here we show that mutation of two amino acid, residues in the active site of human XOR for purine substrates results in, conversion of the substrate preference to AO type. Human XOR and its, Glu803-to-valine (E803V) and Arg881-to-methionine (R881M) mutants were, expressed in an Escherichia coli system. The E803V mutation almost, completely abrogated the activity towards hypoxanthine as a substrate, but, very weak activity towards xanthine remained. On the other hand, the R881M, mutant lacked activity towards xanthine, but retained slight activity, towards hypoxanthine. Both mutants, however, exhibited significant, aldehyde oxidase activity. The crystal structure of E803V mutant of human, XOR was determined at 2.6 A resolution. The overall molybdopterin domain, structure of this mutant closely resembles that of bovine milk XOR; amino, acid residues in the active centre pocket are situated at very similar, positions and in similar orientations, except that Glu803 was replaced by, valine, indicating that the decrease in activity towards purine substrate, is not due to large conformational change in the mutant enzyme. Unlike, wild-type XOR, the mutants were not subject to time-dependent inhibition, by allopurinol. | Xanthine oxidase (oxidoreductase; XOR) and aldehyde oxidase (AO) are, similar in protein structure and prosthetic group composition, but differ, in substrate preference. Here we show that mutation of two amino acid, residues in the active site of human XOR for purine substrates results in, conversion of the substrate preference to AO type. Human XOR and its, Glu803-to-valine (E803V) and Arg881-to-methionine (R881M) mutants were, expressed in an Escherichia coli system. The E803V mutation almost, completely abrogated the activity towards hypoxanthine as a substrate, but, very weak activity towards xanthine remained. On the other hand, the R881M, mutant lacked activity towards xanthine, but retained slight activity, towards hypoxanthine. Both mutants, however, exhibited significant, aldehyde oxidase activity. The crystal structure of E803V mutant of human, XOR was determined at 2.6 A resolution. The overall molybdopterin domain, structure of this mutant closely resembles that of bovine milk XOR; amino, acid residues in the active centre pocket are situated at very similar, positions and in similar orientations, except that Glu803 was replaced by, valine, indicating that the decrease in activity towards purine substrate, is not due to large conformational change in the mutant enzyme. Unlike, wild-type XOR, the mutants were not subject to time-dependent inhibition, by allopurinol. | ||
| - | |||
| - | ==Disease== | ||
| - | Known diseases associated with this structure: Ataxia, early-onset, with oculomotor apraxia and hypoalbuminemia OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=606350 606350]], Coenzyme Q10 deficiency OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=606350 606350]] | ||
==About this Structure== | ==About this Structure== | ||
| - | 2E1Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with BCT, CA, FES, FAD, MTE, MOM and SAL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 2E1Q is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=BCT:'>BCT</scene>, <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=FES:'>FES</scene>, <scene name='pdbligand=FAD:'>FAD</scene>, <scene name='pdbligand=MTE:'>MTE</scene>, <scene name='pdbligand=MOM:'>MOM</scene> and <scene name='pdbligand=SAL:'>SAL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2E1Q OCA]. |
==Reference== | ==Reference== | ||
| Line 35: | Line 31: | ||
[[Category: xanthine oxidase]] | [[Category: xanthine oxidase]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Wed Jan 23 13:32:24 2008'' |
Revision as of 11:32, 23 January 2008
|
Crystal Structure of Human Xanthine Oxidoreductase mutant, Glu803Val
Overview
Xanthine oxidase (oxidoreductase; XOR) and aldehyde oxidase (AO) are, similar in protein structure and prosthetic group composition, but differ, in substrate preference. Here we show that mutation of two amino acid, residues in the active site of human XOR for purine substrates results in, conversion of the substrate preference to AO type. Human XOR and its, Glu803-to-valine (E803V) and Arg881-to-methionine (R881M) mutants were, expressed in an Escherichia coli system. The E803V mutation almost, completely abrogated the activity towards hypoxanthine as a substrate, but, very weak activity towards xanthine remained. On the other hand, the R881M, mutant lacked activity towards xanthine, but retained slight activity, towards hypoxanthine. Both mutants, however, exhibited significant, aldehyde oxidase activity. The crystal structure of E803V mutant of human, XOR was determined at 2.6 A resolution. The overall molybdopterin domain, structure of this mutant closely resembles that of bovine milk XOR; amino, acid residues in the active centre pocket are situated at very similar, positions and in similar orientations, except that Glu803 was replaced by, valine, indicating that the decrease in activity towards purine substrate, is not due to large conformational change in the mutant enzyme. Unlike, wild-type XOR, the mutants were not subject to time-dependent inhibition, by allopurinol.
About this Structure
2E1Q is a Single protein structure of sequence from Homo sapiens with , , , , , and as ligands. Full crystallographic information is available from OCA.
Reference
Human xanthine oxidase changes its substrate specificity to aldehyde oxidase type upon mutation of amino acid residues in the active site: roles of active site residues in binding and activation of purine substrate., Yamaguchi Y, Matsumura T, Ichida K, Okamoto K, Nishino T, J Biochem (Tokyo). 2007 Apr;141(4):513-24. Epub 2007 Feb 14. PMID:17301077
Page seeded by OCA on Wed Jan 23 13:32:24 2008
Categories: Homo sapiens | Single protein | Ichida, K. | Matsumura, T. | Nishino, T. | Okamoto, K. | Yamaguchi, Y. | BCT | CA | FAD | FES | MOM | MTE | SAL | 2fe-2s | Fad | Molybdenum cofactor | Oxidoreductase | Xanthine oxidase
