1Baylor College of Medicine, Department of Neurology, One Baylor Plaza, Houston, TX 77030, USA.
Suppression of heterocyst differentiation in Anabaena PCC 7120 by a cosmid carrying wild-type genes encoding enzymes for fatty acid synthesis
Article first published online: 17 JAN 2006
FEMS Microbiology Letters
Volume 151, Issue 1, pages 23–30, June 1997
How to Cite
Bauer, C.C., Ramaswamy, K.S., Endley, S., Scappino, L.A., Golden, J.W. and Haselkorn, R. (1997), Suppression of heterocyst differentiation in Anabaena PCC 7120 by a cosmid carrying wild-type genes encoding enzymes for fatty acid synthesis. FEMS Microbiology Letters, 151: 23–30. doi: 10.1111/j.1574-6968.1997.tb10390.x
- Issue published online: 17 JAN 2006
- Article first published online: 17 JAN 2006
- Received 8 January 1997, Revised 3 March 1997, Accepted 4 March 1997
- Heterocyst differentiation;
- Anabaena PCC 7120;
A cosmid containing a wild-type Anabaena PCC 7120 DNA fragment was found to suppress heterocyst differentiation, creating a Het phenotype in an otherwise wild-type strain. Curing of the cosmid restored the full wild-type Het+ Nif+ phenotype. The cosmid contains at least four genes encoding proteins with significant sequence similarity to enzymes involved in the synthesis of fatty acids. Selection for Nif+ revertants of the suppressed strain yielded modified cosmids, one of which contained a 10.2-kb transposon, Tas1, inserted into the promoter region of a gene encoding a protein with acyl carrier and β-keto reductase domains. This gene, called hetN, was shown previously by Black and Wolk (J. Bacteriol. (1994) 176, 2282–2292) to inhibit heterocyst differentiation when present alone on a plasmid. Oddly, hetN gene transcription is detected later than 6 h into heterocyst differentiation.