Đang chuẩn bị liên kết để tải về tài liệu:
Báo cáo khoa học: Identification of ATP-NADH kinase isozymes and their contribution to supply of NADP(H) in Saccharomyces cerevisiae
Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
ATP-NAD kinase phosphorylates NAD to produce NADP by using ATP, whereas ATP-NADH kinase phosphorylates both NAD and NADH. Three NAD kinase homologues, namely, ATP-NAD kinase (Utr1p), ATP-NADH kinase (Pos5p) and function-unknown Yel041wp (Yef1p), are found in the yeastSaccharomyces cerevisiae. In this study, Yef1p was identified as an ATP-NADH kinase. The ATP-NADH kinase activity of Utr1p was also confirmed. | ềFEBS Journal Identification of ATP-NADH kinase isozymes and their contribution to supply of NADP H in Saccharomyces cerevisiae Feng Shi1 2 Shigeyuki Kawai1 Shigetarou Mori1 Emi Kono1 and Kousaku Murata1 1 Department of Basic and Applied Molecular Biotechnology Division of Food and BiologicalScience Graduate Schoolof Agriculture Kyoto University Uji Kyoto Japan 2 Schoolof Biotechnology Southern Yangtze University Wuxi Jiangsu China Keywords ATP-NADH kinase Pos5p Saccharomyces cerevisiae Utr1p Yef1p Correspondence K. Murata Department of Basic and Applied Molecular Biotechnology Division of Food and Biological Science Graduate School of Agriculture Kyoto University Uji Kyoto 611-0011 Japan Fax 81 774 38 3767 Tel 81 774 38 3766 E-mail kmurata@kais.kyoto-u.ac.jp Received 23 August 2004 revised 25 April 2005 accepted 3 May 2005 doi 10.1111 j.1742-4658.2005.04749.x ATP-NAD kinase phosphorylates NAD to produce NADP by using ATP whereas ATP-NADH kinase phosphorylates both NAD and NADH. Three NAD kinase homologues namely ATP-NAD kinase Utr1p ATP-NADH kinase Pos5p and function-unknown Yel041wp Yef1p are found in the yeast Saccharomyces cerevisiae. In this study Yef1p was identified as an ATP-NADH kinase. The ATP-NADH kinase activity of Utr1p was also confirmed. Thus the three NAD kinase homologues were biochemically identified as ATP-NADH kinases. The phenotypic analysis of the single double and triple mutants which was unexpectedly found to be viable for UTR1 YEF1 and POS5 demonstrated the critical contribution of Pos5p to mitochondrial function and survival at 37 C and the critical contribution of Utr1p to growth in low iron medium. The contributions of the other two enzymes were also demonstrated however these were observed only in the absence of the critical contributor which was supported by complementation for some pos5 phenotypes by the overexpression of UTR1 and YEF1. The viability of the triple mutant suggested that a novel enzyme whose primary structure is .