CHARACTERIZATION OF DEVA, A GENE REQUIRED FOR THE MATURATION OF PROHETEROCYSTS IN THE CYANOBACTERIUM ANABAENA SP STRAIN PCC-7120

Citation
I. Maldener et al., CHARACTERIZATION OF DEVA, A GENE REQUIRED FOR THE MATURATION OF PROHETEROCYSTS IN THE CYANOBACTERIUM ANABAENA SP STRAIN PCC-7120, Journal of bacteriology, 176(24), 1994, pp. 7543-7549
Citations number
45
Categorie Soggetti
Microbiology
Journal title
ISSN journal
00219193
Volume
176
Issue
24
Year of publication
1994
Pages
7543 - 7549
Database
ISI
SICI code
0021-9193(1994)176:24<7543:CODAGR>2.0.ZU;2-B
Abstract
Mutant M7, obtained by transposon mutagenesis of the cyanobacterium An abaena sp. strain PCC 7120, is impaired in the development of mature h eterocysts. Under aerobic conditions, the mutant is unable to fix N-2 because of a deficiency of at least mo components of the oxygen-protec tive mechanisms: a hemoprotein-coupled oxidative reaction and heterocy st specific glycolipids. DNA contiguous with the inserted transposon w as recovered from the mutant and sequenced. The transposon had inserte d itself within a 732-bp open reading frame designated devA. The wild- type form of devA, obtained from a lambda-EMBL3 library of Anabaena sp . DNA, had the identical sequence. Directed mutagenesis of devA in the wild-type strain showed that the phenotype of the mutant was caused b y insertion of the transposon. The wild-type form of devA on a shuttle vector complemented the mutation in M7. Expression of devA by whole f ilaments, monitored following nitrogen stepdown by using luxAB as the reporter, increased ca. eightfold during differentiation; the increase within differentiating cells was much greater. The deduced sequence o f the DevA protein shows strong similarity to the ATP-binding subunit of binding protein-dependent transport systems. The product of devA ma y, therefore, be a component of a periplasmic permease that is require d for the transition from a proheterocyst to a mature, nitrogen-fixing heterocyst.