Tn5 mutagenesis of Anabaena sp. strain PCC 7120: isolation of a new mutant unable to grow without combined nitrogen.
نویسندگان
چکیده
Methylation by Ava methylases in Escherichia coli increases the efficiency to transfer of Tn5 in pBR322bla:: Tn5 from E. coli to Anabaena sp. strain PCC 7120 by conjugation. Following conjugation, Tn5 but not pBR322 sequences were found at many different positions in the Anabaena chromosome. This procedure was used to mutagenize, tag, and clone a previously unrecognized gene required for nitrogen fixation in this Anabaena sp.
منابع مشابه
Isolation and complementation of nitrogen fixation mutants of the cyanobacterium Anabaena sp. strain PCC 7120.
Approximately 140 mutants of Anabaena sp. strain PCC 7120 unable to grow aerobically on media lacking fixed nitrogen (Fix-) were isolated after mutagenesis with diethyl sulfate and penicillin enrichment. A large cosmid library of wild-type Anabaena sp. strain PCC 7120 DNA was constructed in a mini-RK-2 shuttle vector, and seven mutants representing several morphologically abnormal heterocyst ph...
متن کاملIdentification of the active site of HetR protease and its requirement for heterocyst differentiation in the cyanobacterium Anabaena sp. strain PCC 7120.
HetR is a serine-type protease required for heterocyst differentiation in heterocystous cyanobacteria under conditions of nitrogen deprivation. We have identified the active Ser residue of HetR from Anabaena sp. strain PCC 7120 by site-specific mutagenesis. By changing the S152 residue to an Ala residue, the mutant protein cannot be labeled by Dansyl fluoride, a specific serine-type protein inh...
متن کاملhetC, a gene coding for a protein similar to bacterial ABC protein exporters, is involved in early regulation of heterocyst differentiation in Anabaena sp. strain PCC 7120.
Transposon-generated mutant C3 of Anabaena sp. strain PCC 7120 is unable to form heterocysts upon deprivation of combined nitrogen but forms a pattern of spaced, weakly fluorescent cells after 2 days of deprivation. Sequence analysis of chromosomal DNA adjacent to the ends of transposon Tn5-1058 in mutant C3 showed a 1,044-amino-acid open reading frame, designated hetC, whose predicted protein ...
متن کاملAnabaena sp. strain PCC 7120 ntcA gene required for growth on nitrate and heterocyst development.
The Anabaena sp. strain PCC 7120 ntcA (bifA) gene encodes a sequence-specific DNA-binding protein, NtcA (BifA, VF1) that interacts with the upstream region of several genes, including glnA, xisA, rbcL, and nifH. We have constructed a ntcA null mutant by interrupting the gene with an omega Spr-Smr cassette. The ntcA mutant was not able to grow with nitrate or atmospheric dinitrogen as the sole n...
متن کاملAn increase in the level of 2-oxoglutarate promotes heterocyst development in the cyanobacterium Anabaena sp. strain PCC 7120.
In the filamentous cyanobacterium Anabaena sp. strain PCC 7120, a starvation of combined nitrogen induces differentiation of heterocysts, cells specialized in nitrogen fixation. How do filaments perceive the limitation of the source of combined nitrogen, and what determines the proportion of heterocysts? In cyanobacteria, 2-oxoglutarate provides a carbon skeleton for the incorporation of inorga...
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ورودعنوان ژورنال:
- Journal of bacteriology
دوره 171 10 شماره
صفحات -
تاریخ انتشار 1989