JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Gorski, L.
Right arrow Articles by Kaiser, D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Gorski, L.
Right arrow Articles by Kaiser, D.

Journal of Bacteriology, November 1998, p. 5896-5905, Vol. 180, No. 22
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.

Targeted Mutagenesis of sigma 54 Activator Proteins in Myxococcus xanthus

Lisa Gorski and Dale Kaiser*

Department of Biochemistry and Department of Developmental Biology, Stanford University School of Medicine, Stanford, California 94305-5329

Received 19 December 1997/Accepted 9 September 1998

Myxococcus xanthus DNA segments related to the highly conserved central sequence of sigma 54 activator proteins have been investigated. A genetic technique designed to inactivate a gene that encodes such an activator by inserting a plasmid-borne internal fragment of the putative gene has been tested. When the internal fragment inserted by homologous recombination into the corresponding chromosomal locus, the expected duplication of the gene was observed by Southern hybridization. The single restriction fragment characteristic of each segment was replaced in the insertion strains by two hybridizing fragments, and one of these fragments hybridized with the kanamycin resistance gene of the plasmid vector. The combined molecular weights of the two fragments from the insertion strains were equal to the molecular weight of the original fragment plus the expected molecular weight contributed by the vector. In the duplication, one copy is expected to have an N-terminal deletion and the other copy is expected to have a C-terminal deletion. In most cases, the net result should be loss of activator function. If an activator is essential for vegetative growth, then it should not be possible to obtain the insertion strain by plasmid integration. Indeed, integrants for three of the segments were not obtained in repeated trials; however, a plausible explanation for these results other than lethality can be offered. Of the seven insertions validated by Southern hybridization, four strains exhibited defects in the development of fruiting bodies. One of these failed to develop in submerged culture, though it developed normally on agar. The other three showed arrested development of fruiting bodies, each at a morphologically different stage of aggregation. One of the mutants may be defective in the reception pathway of A-signal.

* Corresponding author. Mailing address: Department of Biochemistry and Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305-5329. Phone: (650) 723-6165. Fax: (650) 725-7739. E-mail: Luttman{at}cmgm.stanford.edu.

Journal of Bacteriology, November 1998, p. 5896-5905, Vol. 180, No. 22
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 1998 by the American Society for Microbiology. All rights reserved.