4z85: Difference between revisions
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
''' | ==Crystal structur of Pseudomonas fluorescens 2-nitrobenzoate 2-nitroreductase NbaA== | ||
<StructureSection load='4z85' size='340' side='right' caption='[[4z85]], [[Resolution|resolution]] 1.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4z85]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4Z85 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4Z85 FirstGlance]. <br> | |||
</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4z85 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4z85 OCA], [http://pdbe.org/4z85 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4z85 RCSB], [http://www.ebi.ac.uk/pdbsum/4z85 PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The bacterial 2-nitroreductase NbaA is the primary enzyme initiating the degradation of 2-nitrobenzoate (2-NBA), and its activity is controlled by posttranslational modifications. To date, the structure of NbaA remains to be elucidated. In this study, the crystal structure of a Cys194Ala NbaA mutant was determined to a 1.7-A resolution. The substrate analog 2-NBA methyl ester was used to decipher the substrate binding site by inhibition of the wild-type NbaA protein. Tandem mass spectrometry showed that 2-NBA methyl ester produced a 2-NBA ester bond at the Tyr193 residue in the wild-type NbaA but not residues in the Tyr193Phe mutant. Moreover, covalent binding of the 2-NBA methyl ester to Tyr193 reduced the reactivity of the Cys194 residue on the peptide link. The Tyr193 hydroxyl group was shown to be essential for enzyme catalysis, as a Tyr193Phe mutant resulted in fast dissociation of flavin mononucleotide (FMN) from the protein with the reduced reactivity of Cys194. FMN binding to NbaA varied with solution NaCl concentration, which was related to the catalytic activity but not to cysteine reactivity. These observations suggest that the Cys194 reactivity is negatively affected by a posttranslational modification of the adjacent Tyr193 residue, which interacts with FMN and the substrate in the NbaA catalytic site. | |||
Structural and Mechanistic Insights into the Pseudomonas fluorescens 2-Nitrobenzoate 2-Nitroreductase NbaA.,Kim YH, Song W, Kim JS, Jiao L, Lee K, Ha NC Appl Environ Microbiol. 2015 Aug;81(15):5266-77. doi: 10.1128/AEM.01289-15. Epub , 2015 May 29. PMID:26025888<ref>PMID:26025888</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 4z85" style="background-color:#fffaf0;"></div> | |||
[[Category: | == References == | ||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Ha, N C]] | |||
[[Category: Jiao, L]] | [[Category: Jiao, L]] | ||
[[Category: | [[Category: Kim, J S]] | ||
[[Category: | [[Category: 2-nitrobenzoate methyl ester]] | ||
[[Category: Cysteine reactivity]] | |||
[[Category: Fmn-binding site]] | |||
[[Category: Oxidoreductase]] | |||
[[Category: Tyrosine modification]] | |||
Revision as of 20:04, 20 January 2016
Crystal structur of Pseudomonas fluorescens 2-nitrobenzoate 2-nitroreductase NbaACrystal structur of Pseudomonas fluorescens 2-nitrobenzoate 2-nitroreductase NbaA
Structural highlights
Publication Abstract from PubMedThe bacterial 2-nitroreductase NbaA is the primary enzyme initiating the degradation of 2-nitrobenzoate (2-NBA), and its activity is controlled by posttranslational modifications. To date, the structure of NbaA remains to be elucidated. In this study, the crystal structure of a Cys194Ala NbaA mutant was determined to a 1.7-A resolution. The substrate analog 2-NBA methyl ester was used to decipher the substrate binding site by inhibition of the wild-type NbaA protein. Tandem mass spectrometry showed that 2-NBA methyl ester produced a 2-NBA ester bond at the Tyr193 residue in the wild-type NbaA but not residues in the Tyr193Phe mutant. Moreover, covalent binding of the 2-NBA methyl ester to Tyr193 reduced the reactivity of the Cys194 residue on the peptide link. The Tyr193 hydroxyl group was shown to be essential for enzyme catalysis, as a Tyr193Phe mutant resulted in fast dissociation of flavin mononucleotide (FMN) from the protein with the reduced reactivity of Cys194. FMN binding to NbaA varied with solution NaCl concentration, which was related to the catalytic activity but not to cysteine reactivity. These observations suggest that the Cys194 reactivity is negatively affected by a posttranslational modification of the adjacent Tyr193 residue, which interacts with FMN and the substrate in the NbaA catalytic site. Structural and Mechanistic Insights into the Pseudomonas fluorescens 2-Nitrobenzoate 2-Nitroreductase NbaA.,Kim YH, Song W, Kim JS, Jiao L, Lee K, Ha NC Appl Environ Microbiol. 2015 Aug;81(15):5266-77. doi: 10.1128/AEM.01289-15. Epub , 2015 May 29. PMID:26025888[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|
| ||||||||||||||