Open AccessHigh CO2 Requiring Mutant of Anacystis nidulans R2
Author(s) -
Yizhak Marcus,
Rakefet Schwarz,
Devorah Friedberg,
Aaron Kaplan
Publication year - 1986
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.82.2.610
Subject(s) - photosynthesis , mutant , carboxylation , rubisco , extracellular , cyanobacteria , ribulose , intracellular , chemistry , diffusion , biophysics , pyruvate carboxylase , biochemistry , botany , wild type , biology , gene , physics , genetics , enzyme , bacteria , catalysis , thermodynamics
Some physiological characteristics of a mutant (E(1)) of Anacystis nidulans R(2), incapable of growing at air level of CO(2), are described. E(1) is capable of accumulating inorganic carbon (C(i)) internally as efficiently as the wild type (R(2)). The apparent photosynthetic affinity for C(i) in E(1), however, is some 1000 times lower than that of R(2). The kinetic parameters of ribulose 1,5-bisphosphate carboxylase/oxygenase from E(1) are similar to those observed in R(2). The mutant appears to be defective in its ability to utilize the intracellular C(i) pool for photosynthesis and depends on extracellular supply of Ci in the form of CO(2). The very high apparent photosynthetic K(m) (CO(2)) of the mutant indicate a large diffusion resistance for CO(2). Data obtained here are used to calculate the permeability coefficient for CO(2) between the bulk medium and the carboxylation site of cyanobacteria.