Work

Characterization of a gene controlling heterocyst differentiation in the cyanobacterium Anabaena 7120.

Year: 1991

Type: preprint

Abstract: Anabaena 7120 mutant 216 fails to differentiate heterocyst. We previously identified a 2.4-kb wild-type DNA fragment able to complement this mutant. We show here that the sequence of this fragment contains a single open reading frame (hetR), encoding a 299-amino-acid protein. Conjugation of deletion subclones of this fragment into strain 216 showed that the hetR-coding region is both necessary and sufficient for complementation of the Het- phenotype. The mutation in 216 is located at nucleotide 535 in the hetR gene, converting a serine at position 179 in the wild-type protein to an asparagine in the mutant. Interruption of the hetR gene in wild-type cells results in a mutant phenotype identical to that of 216. Both 216 and wild-type cells containing wild-type hetR on a plasmid display increased frequency of heterocysts, even on media containing fixed nitrogen. These results suggest that hetR encodes a product that is not only essential for but also controls heterocyst development. This putative regulatory protein lacks known structural motifs characteristic of transcription factors and probably acts at a level one or more steps removed from its target genes.

Source: Genes & Development

DOI: 10.1101/gad.5.2.321

Authors: W J Buikema, R Haselkorn

Institution: University of Chicago

Language: English

Topic: Bacterial Genetics and Biotechnology

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: bronze

Funders: American Cancer Society, National Institutes of Health, National Institute of General Medical Sciences

Awards: DIFFERENTIATION IN NITROGEN FIXING BLUE GREEN ALGAE, GENE REARRANGEMENT IN CYANOBACTERIAL HETEROCYST