Crystal Structures of Pyruvate Phosphate Dikinase from Maize Revealed an Alternative Conformation in the Swiveling-Domain Motion

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• 作者：Tsugumi Nakanishi ; Toru Nakatsu ; Makoto Matsuoka ; Kanzo Sakata ; and Hiroaki Kato
• 刊名：Biochemistry
• 出版年：2005
• 出版时间：February 1, 2005
• 年：2005
• 卷：44
• 期：4
• 页码：1136 - 1144
• 全文大小：778K
• 年卷期：v.44,no.4(February 1, 2005)
• ISSN：1520-4995

文摘

Pyruvate phosphate dikinase (PPDK) reversibly catalyzes the conversion of ATP, phosphate,and pyruvate into AMP, pyrophosphate, and phosphoenolpyruvate (PEP), respectively. Since the nucleotidebinding site (in the N-terminal domain) and the pyruvate/PEP binding site (in the C-terminal domain) areseparated by ~45 Å, it has been proposed that an intermediary domain, called the central domain, swivelsbetween these remote domains to transfer the phosphate. However, no direct structural evidence for theswiveling central domain has been found. In this study, the crystal structures of maize PPDK with andwithout PEP have been determined at 2.3 Å resolution. These structures revealed that the central domainis located near the pyruvate/PEP binding C-terminal domain, in contrast to the PPDK from Clostridiumsymbiosum, wherein the central domain is located near the nucleotide-binding N-terminal domain. Structuralcomparisons between the maize and C. symbiosum PPDKs demonstrated that the swiveling motion of thecentral domain consists of a rotation of at least 92 and a translation of 0.5 Å. By comparing the maizePPDK structures with and without PEP, we have elucidated the mode of binding of PEP to the C-terminaldomain and the induced conformational changes in the central domain.