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Title: Modifications of und rbcS in und Synechococcus sp. PCC7942 resulted in high CO sub 2 requiring mutants

Abstract

High CO{sub 2} requiring mutants (HCR), capable of growing in the presence of kanamycin, were obtained following transformation with a construct containing {und nptII} in the coding region of rbcS (encoding for the small subunit (SS) of Rubisco). The apparent photosynthetic affinity for inorganic carbon was very low in mutant EK6 whereas in mutant JR12 it was only slightly lower than in high-CO{sub 2}-grown wild type. Southern analysis indicated double crossing over in the case of EK6. In mutant JR12 Southern analysis revealed some rearrangement and a deletion of a region downstream fro {und rbcS}. Western analysis demonstrated normal SS in JR12 but a larger (by about 3 kD) SS in EK6. Sequence analysis indicated that the latter was the result of fusion between {und rbcS} and the flanking region of {und nptII}.

Authors:
; ; ; ;  [1]
  1. (Hebrew Univ. of Jerusalem (Israel))
Publication Date:
OSTI Identifier:
5841377
Alternate Identifier(s):
OSTI ID: 5841377
Report Number(s):
CONF-9007196--
Journal ID: ISSN 0079-2241; CODEN: PPYSA
Resource Type:
Conference
Resource Relation:
Journal Name: Plant Physiology, Supplement; (USA); Journal Volume: 93:1; Conference: Annual meeting of the American Society of Plant Physiologists, Indianapolis, IN (USA), 29 Jul - 2 Aug 1990
Country of Publication:
United States
Language:
English
Subject:
59 BASIC BIOLOGICAL SCIENCES; ALGAE; MUTANTS; CARBON DIOXIDE; METABOLISM; PHOTOSYNTHESIS; RIBULOSE DIPHOSPHATE CARBOXYLASE; CARBON COMPOUNDS; CARBON OXIDES; CARBON-CARBON LYASES; CARBOXY-LYASES; CHALCOGENIDES; CHEMICAL REACTIONS; ENZYMES; LYASES; OXIDES; OXYGEN COMPOUNDS; PHOTOCHEMICAL REACTIONS; PLANTS; SYNTHESIS 550500* -- Metabolism

Citation Formats

Schwarz, R., Liehman-Hurwitz, J., Martinez, F., Reinhold, L., and Kaplan, A.. Modifications of und rbcS in und Synechococcus sp. PCC7942 resulted in high CO sub 2 requiring mutants. United States: N. p., 1990. Web.
Schwarz, R., Liehman-Hurwitz, J., Martinez, F., Reinhold, L., & Kaplan, A.. Modifications of und rbcS in und Synechococcus sp. PCC7942 resulted in high CO sub 2 requiring mutants. United States.
Schwarz, R., Liehman-Hurwitz, J., Martinez, F., Reinhold, L., and Kaplan, A.. Tue . "Modifications of und rbcS in und Synechococcus sp. PCC7942 resulted in high CO sub 2 requiring mutants". United States. doi:.
@article{osti_5841377,
title = {Modifications of und rbcS in und Synechococcus sp. PCC7942 resulted in high CO sub 2 requiring mutants},
author = {Schwarz, R. and Liehman-Hurwitz, J. and Martinez, F. and Reinhold, L. and Kaplan, A.},
abstractNote = {High CO{sub 2} requiring mutants (HCR), capable of growing in the presence of kanamycin, were obtained following transformation with a construct containing {und nptII} in the coding region of rbcS (encoding for the small subunit (SS) of Rubisco). The apparent photosynthetic affinity for inorganic carbon was very low in mutant EK6 whereas in mutant JR12 it was only slightly lower than in high-CO{sub 2}-grown wild type. Southern analysis indicated double crossing over in the case of EK6. In mutant JR12 Southern analysis revealed some rearrangement and a deletion of a region downstream fro {und rbcS}. Western analysis demonstrated normal SS in JR12 but a larger (by about 3 kD) SS in EK6. Sequence analysis indicated that the latter was the result of fusion between {und rbcS} and the flanking region of {und nptII}.},
doi = {},
journal = {Plant Physiology, Supplement; (USA)},
number = ,
volume = 93:1,
place = {United States},
year = {Tue May 01 00:00:00 EDT 1990},
month = {Tue May 01 00:00:00 EDT 1990}
}

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  • A total of 24 high CO{sub 2}-requiring-mutants of the cyanobacterium Synechococcus PCC7942 have been isolated and partially characterized. These chemically induced mutants are able to grow at 1% CO{sub 2}, on agar media, but are incapable of growth at air levels of CO{sub 2}. All the mutants were able to accumulate inorganic carbon (C{sub i}) to levels similar to or higher than wild type cells, but were apparently unable to generate intracellular CO{sub 2}. Compared to wild-type cells, Type I mutants had the following characteristics: fast C{sub i} release, normal internal C{sub i} pool, normal carbonic anhydrase (CA) activity inmore » crude extracts, reduced internal exchange of {sup 18}O from {sup 18}O-labeled CO{sub 2}, 1% CO{sub 2} requirement for growth in liquid media, normal affinity of carboxylase for CO{sub 2}, and long, rod-like carboxysomes. Type II mutants had the following characteristics: slow C{sub i} release, increased internal C{sub i} pool, normal CA activity in crude extracts, normal internal {sup 18}O exchange, a 3% CO{sub 2} requirement for growth in liquid media, high carboxylase activity, normal affinity of carboxylase for CO{sub 2}, and normal carboxysome structure but increased in numbers per cell. Both mutant phenotypes appear to have genetic lesions that result in an inability to convert intracellular HCO{sub 3}{sup {minus}} to CO{sub 2} inside the carboxysome. The features of the type I mutants are consistent with a scenario where carboxysomal CA has been mistargeted to the cytosol. The characteristics of the type II phenotype appear to be most consistent with a scenario where CA activity is totally missing from the cell except for the fact that cell extracts have normal CA activity. Alternatively the Type II mutants may have a lesion in their capacity for H{sup +} import during photosynthesis.« less
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  • We present high resolution photoassociation spectroscopy of RbCs molecules in (2)0{sup +} long-range state below the Rb(5S{sub 1/2}) + Cs(6P{sub 1/2}) asymptote and derive the corresponding C{sub 6} coefficient, which is used to revise the potential energy curves. The excited state molecules are produced in a dual-species dark spontaneous force optical trap and detected by ionizing ground state molecules after spontaneous decay, using a high sensitive time-of-flight mass spectrum. With the help of resonance-enhanced two-photon ionization technique, we obtain considerable high resolution photoassociation spectrum with rovibrational states, some of which have never been observed before. By applying the LeRoy-Bernstein method,more » we assign the vibrational quantum numbers and deduce C{sub 6} coefficient, which agrees with the theoretical value of A{sup 1}Σ{sup +} state correlated to Rb(5S{sub 1/2}) + Cs(6P{sub 1/2}) asymptote. The obtained C{sub 6} coefficient is used to revise the long-range potential energy curve for (2)0{sup +} state, which possesses unique A − b mixing characteristic and can be a good candidate for the production of absolutely ground state molecule.« less