A 2ND NITROGENASE IN VEGETATIVE CELLS OF A HETEROCYST-FORMING CYANOBACTERIUM

被引：97

作者：

THIEL, T ^{[1
]}

LYONS, EM ^{[1
]}

ERKER, JC ^{[1
]}

ERNST, A ^{[1
]}

机构：

[1] UNIV KONSTANZ, FAK BIOL, D-78434 CONSTANCE, GERMANY

来源：

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA | 1995年 / 92卷 / 20期

关键词：

ANABAENA; NIF;

D O I：

10.1073/pnas.92.20.9358

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

In many filamentous cyanobacteria nitrogen fixation occurs in differentiated cells called heterocysts. Filamentous strains that do not form heterocysts may fix nitrogen in vegetative cells, primarily under anaerobic conditions. We describe here two functional Mo-dependent nitrogenases in a single organism, the cyanobacterium Anabaena variabilis, Using a lacZ reporter with a fluorescent P-galactoside substrate for in situ localization of gene expression, we have shown that the two clusters of nif genes are expressed independently, One nitrogenase functions only in heterocysts under either aerobic or anaerobic growth conditions, whereas the second nitrogenase functions only under anaerobic conditions in vegetative cells and heterocysts. Differences between the two nif clusters suggest that the nitrogenase that is expressed in heterocysts is developmentally regulated while the other is regulated by environmental factors.

引用

页码：9358 / 9362

页数：5

共 35 条

[1] STUDIES ON NITROGEN-FIXING BLUE-GREEN ALGAE .1. GROWTH AND NITROGEN FIXATION BY ANABAENA-CYLINDRICA LEMM [J].