Open AccessEffect of mutations of residue 340 in the large subunit polypeptide of Rubisco from Anacystis nidulans
Author(s) -
Madgwick Pippa J.,
Parmar Saroj,
Parry Martin A. J.
Publication year - 1998
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1327.1998.2530476.x
Subject(s) - alanine , asparagine , rubisco , carboxylation , biochemistry , histidine , protein subunit , tyrosine , chemistry , residue (chemistry) , biology , stereochemistry , photosynthesis , amino acid , gene , catalysis
Residues 338−342 at the C‐terminal end of loop 6 in the large subunit β/α barrel structure of Rubisco influence specificity towards CO 2 and O 2 . In Anacystis nidulans Rubisco, replacement of alanine 340 by tyrosine or histidine increased the specificity factor by 12−13 %, accompanied by a 25−33 % fall in V c , the rate of carboxylation, while replacement by asparagine increased the specificity factor by 9 % and V c by 19 %. Other mutations did not significantly alter specificity. Alanine 340 does not interact directly with the bisphosphate substrate, thus replacing it with other residues must have indirect effects on the specificity factor and rate of carboxylation.