Identification of the gene encoding the tryptophan synthase β-subunit from Chlamydomonas reinhardtii

Anthony L. Palombella, Susan K. Dutcher

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

We report the isolation of a Chlamydomonas reinhardtii cDNA that encodes the β-subunit of tryptophan synthase (TSB). This cDNA was cloned by functional complementation of a trp-operon-deleted strain of Escherichia coli. Hybridization analysis indicated that the gene exists in a single copy. The predicted amino acid sequence showed the greatest identity to TSB polypeptides from other photosynthetic organisms. With the goal of identifying mutations in the gene encoding this enzyme, we isolated 11 recessive and 1 dominant single-gene mutation that conferred resistance to 5-fluoroindole. These mutations fell into three complementation groups, MAA2, MAA7, and TAR1. In vitro assays showed that mutations at each of these loci affected TSB activity. Restriction fragment-length polymorphism analysis suggested that MAA7 encodes TSB. MAA2 and TAR1 may act to regulate the activity of MAA7 or its protein product.

Original languageEnglish
Pages (from-to)455-464
Number of pages10
JournalPlant Physiology
Volume117
Issue number2
DOIs
StatePublished - 1998

Fingerprint

Dive into the research topics of 'Identification of the gene encoding the tryptophan synthase β-subunit from Chlamydomonas reinhardtii'. Together they form a unique fingerprint.

Cite this