1z75: Difference between revisions
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[[Image:1z75.gif|left|200px]] | [[Image:1z75.gif|left|200px]] | ||
'''Crystal Structure of ArnA dehydrogenase (decarboxylase) domain, R619M mutant''' | {{Structure | ||
|PDB= 1z75 |SIZE=350|CAPTION= <scene name='initialview01'>1z75</scene>, resolution 2.40Å | |||
|SITE= | |||
|LIGAND= <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene> and <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene> | |||
|ACTIVITY= | |||
|GENE= PMRI, YFBG ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=562 Escherichia coli]) | |||
}} | |||
'''Crystal Structure of ArnA dehydrogenase (decarboxylase) domain, R619M mutant''' | |||
==Overview== | ==Overview== | ||
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==About this Structure== | ==About this Structure== | ||
1Z75 is a [ | 1Z75 is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1Z75 OCA]. | ||
==Reference== | ==Reference== | ||
Structure and mechanism of ArnA: conformational change implies ordered dehydrogenase mechanism in key enzyme for polymyxin resistance., Gatzeva-Topalova PZ, May AP, Sousa MC, Structure. 2005 Jun;13(6):929-42. PMID:[http:// | Structure and mechanism of ArnA: conformational change implies ordered dehydrogenase mechanism in key enzyme for polymyxin resistance., Gatzeva-Topalova PZ, May AP, Sousa MC, Structure. 2005 Jun;13(6):929-42. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/15939024 15939024] | ||
[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
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[[Category: rossmann fold]] | [[Category: rossmann fold]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Mar 20 15:31:58 2008'' | ||
Revision as of 16:32, 20 March 2008
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| , resolution 2.40Å | |||||||
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| Ligands: | and | ||||||
| Gene: | PMRI, YFBG (Escherichia coli) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal Structure of ArnA dehydrogenase (decarboxylase) domain, R619M mutant
OverviewOverview
The modification of lipid A with 4-amino-4-deoxy-L-arabinose (Ara4N) allows gram-negative bacteria to resist the antimicrobial activity of cationic antimicrobial peptides and antibiotics such as polymyxin. ArnA is the first enzyme specific to the lipid A-Ara4N pathway. It contains two functionally and physically separable domains: a dehydrogenase domain (ArnA_DH) catalyzing the NAD+-dependent oxidative decarboxylation of UDP-Glucuronic acid (UDP-GlcA), and a transformylase domain that formylates UDP-Ara4N. Here, we describe the crystal structure of the full-length bifunctional ArnA with UDP-GlcA and ATP bound to the dehydrogenase domain. Binding of UDP-GlcA triggers a 17 A conformational change in ArnA_DH that opens the NAD+ binding site while trapping UDP-GlcA. We propose an ordered mechanism of substrate binding and product release. Mutation of residues R619 and S433 demonstrates their importance in catalysis and suggests that R619 functions as a general acid in catalysis. The proposed mechanism for ArnA_DH has important implications for the design of selective inhibitors.
About this StructureAbout this Structure
1Z75 is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
ReferenceReference
Structure and mechanism of ArnA: conformational change implies ordered dehydrogenase mechanism in key enzyme for polymyxin resistance., Gatzeva-Topalova PZ, May AP, Sousa MC, Structure. 2005 Jun;13(6):929-42. PMID:15939024
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