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Sequence analysis of the Brevibacterium lactofermentum trp operon
Molecular & General Genetics : MGG
|September 1, 1987
Summary
This study identifies seven tryptophan (trp) genes in Brevibacterium lactofermentum, revealing their organization and enzyme similarities to E. coli. This enhances understanding of amino acid biosynthesis in this important industrial bacterium.
Area of Science:
- Microbiology
- Molecular Biology
- Biochemistry
Background:
- Brevibacterium lactofermentum is a Gram-positive bacterium significant for industrial amino acid production.
- Understanding tryptophan biosynthesis is crucial for optimizing production in microbial systems.
Purpose of the Study:
- To identify and characterize the tryptophan (trp) biosynthetic genes in Brevibacterium lactofermentum.
- To determine the genetic organization and evolutionary relationships of these trp genes.
Main Methods:
- Complementation tests using tryptophan auxotrophs of B. lactofermentum and Escherichia coli.
- DNA sequencing of a 7725 bp fragment encoding trp genes.
- Bioinformatic analysis of gene sequences and enzyme homology.
Main Results:
- Seven open reading frames (TRPL, TRPE, TRPG, TRPD, TRPC/F, TRPB, TRPA) were identified and mapped.
- The gene organization is identical to Serratia marcescens and distinct from other Gram-positive bacteria.
- B. lactofermentum trp enzymes show greater sequence similarity to E. coli enzymes than to Bacillus subtilis enzymes.
Conclusions:
- The tryptophan gene cluster in B. lactofermentum is conserved in organization with Gram-negative bacteria.
- Enzyme evolution in B. lactofermentum shows a closer resemblance to Gram-negative bacteria, despite its Gram-positive nature.