Role of the Rubisco small subunit. Final report for period May 1, 1997--April 30,2000

Spreitzer, Robert J.

University of Nebraska, Lincoln, NE (United States)

关键词: Chloroplasts;    Oxygenases Structure-Activity Relationships;    Oxygenases;    Ribulose Diphosphate Carboxylase;    59 Basic Biological Sciences;   

DOI  :  10.2172/809467
RP-ID  :  DOE/ER/20261--1
RP-ID  :  FG02-97ER20261
RP-ID  :  809467

美国|英语

来源: UNT Digital Library

【 摘 要 】

CO{sub 2} and O{sub 2} are mutually competitive at the active site of ribulose-1,5-biphosphate (RuBP) carboxylase/oxygenase (Rubisco). Rubisco contains two subunits, each present in eight copies. The 15-kD small subunit is coded by a family of nuclear RbcS genes. Until now, the role of the small subunit in Rubisco structure or catalytic efficiency is not known. Because of other work in eliminating the two RbcS genes in the green algo Chlamydomonas reinhardtii, it is now possible to address questions about the structure-function relationships of the eukaryotic small subunit. There are three specific aims in this project: (1) Alanine scanning mutagenesis is being used to dissect the importance of the {beta}A/{beta}B loop, a feature unique to the eukaryotic small subunit. (2) Random mutagenesis is being used to identify additional residues or regions of the small subunit that are important for holoenzyme assembly and function. (3) Attempts are being made to express foreign small subunits in Chlamydomonas to examine the contribution of small subunits to holoenzyme assembly, catalytic efficiency, and CO{sub 2}/O{sub 2} specificity.