Work

The biosynthesis of tabtoxinine-beta-lactam. Use of specifically 13C-labeled glucose and 13C NMR spectroscopy to identify its biosynthetic precursors.

Year: 1987

Type: article

Abstract: Tabtoxinine-beta-lactam, an irreversible inhibitor of glutamine synthetase is produced by several pathovars of Pseudomonas syringae. We have examined tabtoxinine-beta-lactam biosynthesis, an important and poorly characterized step in pathogenesis caused by this organism. We have identified the biosynthetic precursors of tabtoxinine-beta-lactam by incorporating 13C from specifically 13C-labeled D-glucose precursors and determining the labeling pattern using 13C NMR spectroscopy. Tabtoxinine-beta-lactam is generated by combining a 4-carbon fragment, a 2-carbon fragment, and a single carbon. The 4-carbon fragment arises from aspartic acid, and the 2-carbon unit is donated from carbons 2 and 3 of pyruvate. The 6-carbon backbone of tabtoxinine-beta-lactam arises from the condensation of fragments from aspartate and pyruvate, probably using reactions analogous to the initial steps in the pathway of lysine biosynthesis.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(18)61144-5

Authors: C.J. Unkefer, R.E. London, R.D. Durbin, T.F. Uchytil, P.J. Langston-Unkefer

Institutions: Agricultural Research Service, United States Department of Agriculture, Los Alamos National Laboratory, University of Wisconsin–Madison, National Institute of Environmental Health Sciences

Language: English

Topic: Microbial Natural Products and Biosynthesis

Subfield: Pharmacology

Field: Medicine

Domain: Health Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funder: National Center for Research Resources