|
|
| Line 1: |
Line 1: |
| [[Image:2bll.gif|left|200px]] | | {{Seed}} |
| | [[Image:2bll.png|left|200px]] |
|
| |
|
| <!-- | | <!-- |
| Line 9: |
Line 10: |
| {{STRUCTURE_2bll| PDB=2bll | SCENE= }} | | {{STRUCTURE_2bll| PDB=2bll | SCENE= }} |
|
| |
|
| '''APO-STRUCTURE OF THE C-TERMINAL DECARBOXYLASE DOMAIN OF ARNA'''
| | ===APO-STRUCTURE OF THE C-TERMINAL DECARBOXYLASE DOMAIN OF ARNA=== |
|
| |
|
|
| |
|
| ==Overview==
| | <!-- |
| Modification of the lipid A moiety of lipopolysaccharide by the addition of the sugar 4-amino-4-deoxy-L-arabinose (L-Ara4N) is a strategy adopted by pathogenic Gram-negative bacteria to evade cationic antimicrobial peptides produced by the innate immune system. L-Ara4N biosynthesis is therefore a potential anti-infective target, because inhibiting its synthesis would render certain pathogens more sensitive to the immune system. The bifunctional enzyme ArnA, which is required for L-Ara4N biosynthesis, catalyzes the NAD(+)-dependent oxidative decarboxylation of UDP-glucuronic acid to generate a UDP-4'-keto-pentose sugar and also catalyzes transfer of a formyl group from N-10-formyltetrahydrofolate to the 4'-amine of UDP-L-Ara4N. We now report the crystal structure of the N-terminal formyltransferase domain in a complex with uridine monophosphate and N-5-formyltetrahydrofolate. Using this structure, we identify the active site of formyltransfer in ArnA, including the key catalytic residues Asn(102), His(104), and Asp(140). Additionally, we have shown that residues Ser(433) and Glu(434) of the decarboxylase domain are required for the oxidative decarboxylation of UDP-GlcUA. An E434Q mutant is inactive, suggesting that chemical rather than steric properties of this residue are crucial in the decarboxylation reaction. Our data suggest that the decarboxylase domain catalyzes both hydride abstraction (oxidation) from the C-4' position and the subsequent decarboxylation.
| | The line below this paragraph, {{ABSTRACT_PUBMED_15809294}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 15809294 is the PubMed ID number. |
| | --> |
| | {{ABSTRACT_PUBMED_15809294}} |
|
| |
|
| ==About this Structure== | | ==About this Structure== |
| Line 32: |
Line 36: |
| [[Category: Short chain dehydrogenase]] | | [[Category: Short chain dehydrogenase]] |
| [[Category: Transferase]] | | [[Category: Transferase]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 20:27:41 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Tue Jul 29 08:55:00 2008'' |