期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1983
卷号：80
期号：4
页码：1013-1017
DOI：10.1073/pnas.80.4.1013
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Ribulose-1,5-bisphosphate carboxylase [RuP2Case; 3-phospho-D-glycerate carboxy-lyase (dimerizing), EC 4.1.1.39 ] is composed of eight small subunits (Mr, 14,000) and eight large subunits (Mr, 55,000). Newly synthesized large subunits are associated with two complexes having sedimentation coefficients of 7 and 29 S. Assembly of RuP2Case occurs in isolated intact chloroplasts in the light but not in the dark. When extracts of chloroplasts are treated with ATP or GTP, RuP2Case assembly is accelerated while the 29S large subunit complex is maintained. In the presence of Mg2+, ATP brings about almost complete dissociation of the 29S complex, whereas GTP and a nonhydrolyzable analog of ATP are without effect. These results indicate the existence of a complex set of reactions involving nucleotides, Mg2+, and several putative intermediates in RuP2Case assembly. It is postulated that these reactions at least partly account for the light dependence of RuP2Case assembly. In particular, ATP and GTP promote the assembly of large subunits into RuP2Case.
