Biophysical, biochemical, and physiological characterization of Chlamydomonas reinhardtii mutants with amino acid substitutions at the Ala251 residue in the D1 protein that result in varying levels of photosynthetic competence.

The Journal of Biological Chemistry
A LardansJ E Boynton

Abstract

The QB binding site of the D1 reaction center protein, located within a stromal loop between transmembrane helices IV and V formed by residues Ile219 to Leu272, is essential for photosynthetic electron transport through photosystem II (PSII). We have examined the function of the highly conserved Ala251 D1 residue in this domain in chloroplast transformants of Chlamydomonas reinhardtii and found that Arg, Asp, Gln, Glu, and His substitutions are nonphotosynthetic, whereas Cys, Ser, Pro, Gly, Ile, Val, and Leu substitutions show various alterations in D1 turnover, photosynthesis, and photoautotrophic growth. The latter mutations reduce the rate of QA to QB electron transfer, but this is not necessarily rate-limiting for photoautotrophic growth. The Cys mutant divides and evolves O2 at wild type rates, although it has slightly higher rates of D1 synthesis and turnover and reduced electron transfer between QA and QB. O2 evolution, D1 synthesis, and accumulation in the Ser, Pro, and Gly mutants in high light is reduced, but photoautotrophic growth rate is not affected. In contrast, the Ile, Val, and Leu mutants are impaired in photoautotrophic growth and photosynthesis in both low and high light and have elevated rates of D1 synthes...Continue Reading

References

Jan 1, 1977·Annual Review of Biophysics and Bioengineering·F M Richards
Oct 16, 1992·Biochimica Et Biophysica Acta·R J Debus
Sep 1, 1991·Zeitschrift Für Naturforschung. C, a Journal of Biosciences·B SvenssonS Styring
Oct 24, 1995·Proceedings of the National Academy of Sciences of the United States of America·J M EscoubasP G Falkowski
Aug 1, 1995·Current Biology : CB·J F AllenG Håkansson
Jul 5, 1993·Biochimica Et Biophysica Acta·E M AroB Andersson
Feb 18, 1997·Proceedings of the National Academy of Sciences of the United States of America·N KerenI Ohad
Feb 15, 1992·Proceedings of the National Academy of Sciences of the United States of America·I VassB Andersson
Jul 1, 1984·Proceedings of the National Academy of Sciences of the United States of America·D J KyleC J Arntzen
Jun 1, 1996·Photosynthesis Research·O PrasilP G Falkowski
Jan 1, 1993·Photosynthesis Research·A L Etienne, D Kirilovsky

❮ Previous
Next ❯

Citations

May 5, 2001·Annual Review of Plant Physiology and Plant Molecular Biology·Elizabeth H Harris
Mar 29, 2014·Photosynthesis Research·Alexandra Dubini, Maria L Ghirardi
Oct 24, 1998·Biochimica Et Biophysica Acta·M HipplerJ D Rochaix

❮ Previous
Next ❯

Related Concepts

Related Feeds

ASBMB Publications

The American Society for Biochemistry and Molecular Biology (ASBMB) includes the Journal of Biological Chemistry, Molecular & Cellular Proteomics, and the Journal of Lipid Research. Discover the latest research from ASBMB here.