| Characterization of the aminocarboxycyclopropane-forming enzyme CmaC. | |
| | |
MedLine Citation:
|
PMID: 17209546 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The biosynthesis of the coronamic acid fragment of the pseudomonal phytotoxin coronatine involves construction of the cyclopropane ring from a gamma-chloro-L-allo-Ile intermediate while covalently tethered as a phosphopantetheinyl thioester to the carrier protein CmaD. The cyclopropane-forming catalyst is CmaC, catalyzing an intramolecular displacement of the gamma-Cl group by the alpha carbon. CmaC can be isolated as a Zn2+ protein with about 10-fold higher activity over the apo form. CmaC will not cyclize free gamma-chloro amino acids or their S-N-acetylcysteamine (NAC) thioester derivatives but will recognize some other carrier protein scaffolds. Turnover numbers of 5 min-1 are observed for Zn-CmaC, acting on gamma-chloro-L-aminobutyryl-S-CmaD, generating 1-aminocyclopropane-1-carbonyl (ACC)-S-CmaD. Products were detected either while still tethered to the phosphopantetheinyl prosthetic arm by mass spectrometry or after thioesterase-mediated release and derivatization of the free amino acid. In D2O, CmaC catalyzed exchange of one deuterium into the aminobutyryl moiety of the gamma-Cl-aminoacyl-S-CmaD, whereas the product ACC-S-CmaD lacked the deuterium, consistent with a competition for a gamma-Cl-aminobutyryl alpha-carbanion between reprotonation and cyclization. CmaC-mediated cyclization yielded solely ACC, resulting from C-C bond formation and no azetidine carboxylate from an alternate N-C cyclization. CmaC could cyclize gamma,gamma-dichloroaminobutyryl to the Cl-ACC product but did not cyclize delta- or epsilon-chloroaminoacyl-S-CmaD substrates. |
| | |
Authors:
|
Wendy L Kelly; Michael T Boyne; Ellen Yeh; David A Vosburg; Danica P Galonić; Neil L Kelleher; Christopher T Walsh |
Related Documents
:
|
6258106 - Treatment of huntington disease with gamma-acetylenic gaba an irreversible inhibitor of... 7259166 - Transformation, remodeling and dissociation of achromatic fibres by butyric acid in mit... 975566 - Gamma-carboxyglutamic acid in human urine. 7470766 - Investigation of the antifibrillatory activity of some anticonvulsant gamma-aminobutyri... 1606656 - Unequal hydrolysis of salicylic acid-d-alanine and salicylic acid-l-alanine conjugate i... 2680526 - Excitotoxin-induced myocardial necrosis. |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Biochemistry Volume: 46 ISSN: 0006-2960 ISO Abbreviation: Biochemistry Publication Date: 2007 Jan |
Date Detail:
|
Created Date: 2007-01-09 Completed Date: 2007-02-27 Revised Date: 2007-12-03 |
Medline Journal Info:
|
Nlm Unique ID: 0370623 Medline TA: Biochemistry Country: United States |
Other Details:
|
Languages: eng Pagination: 359-68 Citation Subset: IM |
Affiliation:
|
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Amino Acids
/
biosynthesis*,
chemistry Bacterial Proteins / chemistry, metabolism* Kinetics Mass Spectrometry Pseudomonas syringae / enzymology Substrate Specificity Thiolester Hydrolases / metabolism* |
| Grant Support | |
ID/Acronym/Agency:
|
F32GM7215/GM/NIGMS NIH HHS; GM 067725/GM/NIGMS NIH HHS; GM 20011/GM/NIGMS NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Amino Acids; 0/Bacterial Proteins; 80483-77-8/1-amino-2-ethylcyclopropane-1-carboxylic acid; EC 3.1.2.-/Thiolester Hydrolases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Functional interrogation of the kinome using nucleotide acyl phosphates.
Next Document: Characterization of human UDP-glucose dehydrogenase reveals critical catalytic roles for lysine 220 ...