Related αN- and εN-Methyltransferases Methylate the Large and Small Subunits of Rubisco

Autor: Zhentu Ying, Robert L. Houtz, Malcolm Royer, R. M. Mulligan, Noel Janney
Rok vydání: 1998
Předmět:
Zdroj: Acta Biologica Hungarica. 49:173-184
ISSN: 1588-256X
0236-5383
DOI: 10.1007/bf03542990
Popis: Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is methylated at the ax amino position of the N-terminal methionyl residue of the processed and assembled form of the small subunit (SS), and is also methylated in some species at the epsilon-amino group of lysine-14 in the large subunit (LS). The gene (rbcMT-S) and cDNAs for the SS alphaN-methyltransferase (SSMT) from spinach (Spinach oleracea) have been cloned, sequenced, and expressed. The gene is closely related to a previously characterized LS methyltransferase (Rubisco LSMT) cDNA from pea (Rubisco LSMT) and a Rubisco LSMT gene from tobacco. Sequence analysis of the cDNA and transcript mapping experiments demonstrate that the rbcMT-S pre-mRNAs experience alternative 3' splice site selection, such that mRNAs for a long form with a four amino acid insertion and a short form are expressed at approximately equal abundance. The coding sequence of spinach SSMT includes a putative targeting presequence with sequence identity at a plastid processing site. A N-terminal truncated form of spinach SSMT was expressed and purified from E. coli cells. Both long and short forms of the cDNAs were shown to catalyze methylation of the a amine of the N-terminal methionine of the SS of Rubisco.
Databáze: OpenAIRE
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