TY - JOUR
T1 - Structure analysis of archaeal AMP phosphorylase reveals two unique modes of dimerization
AU - Nishitani, Yuichi
AU - Aono, Riku
AU - Nakamura, Akira
AU - Sato, Takaaki
AU - Atomi, Haruyuki
AU - Imanaka, Tadayuki
AU - Miki, Kunio
N1 - Funding Information:
We would like to thank Dr. Masahiro Fujihashi for his support and beamline scientists at the Photon Factory and SPring-8. This work was supported by the Targeted Proteins Research Program from the Ministry of Education, Culture, Sports, Science and Technology, Japan . The synchrotron radiation experiments were performed at the Photon Factory and SPring-8 with the approval of the Photon Factory Advisory Committee and the Japan Synchrotron Radiation Research Institute.
PY - 2013/8/9
Y1 - 2013/8/9
N2 - AMP phosphorylase (AMPpase) catalyzes the initial reaction in a novel AMP metabolic pathway recently found in archaea, converting AMP and phosphate into adenine and ribose 1,5-bisphosphate. Gel-filtration chromatography revealed that AMPpase from Thermococcus kodakarensis (Tk-AMPpase) forms an exceptionally large macromolecular structure (> 40-mers) in solution. To investigate its unique multimerization feature, we determined the first crystal structures of Tk-AMPpase, in the apo-form and in complex with substrates. Structures of two truncated forms of Tk-AMPpase (Tk-AMPpaseΔN84 and Tk-AMPpaseΔC10) clarified that this multimerization is achieved by two dimer interfaces within a single molecule: one by the central domain and the other by the C-terminal domain, which consists of an unexpected domain-swapping interaction. The N-terminal domain, characteristic of archaeal enzymes, is essential for enzymatic activity, participating in multimerization as well as domain closure of the active site upon substrate binding. Moreover, biochemical analysis demonstrated that the macromolecular assembly of Tk-AMPpase contributes to its high thermostability, essential for an enzyme from a hyperthermophile. Our findings unveil a unique archaeal nucleotide phosphorylase that is distinct in both function and structure from previously known members of the nucleoside phosphorylase II family.
AB - AMP phosphorylase (AMPpase) catalyzes the initial reaction in a novel AMP metabolic pathway recently found in archaea, converting AMP and phosphate into adenine and ribose 1,5-bisphosphate. Gel-filtration chromatography revealed that AMPpase from Thermococcus kodakarensis (Tk-AMPpase) forms an exceptionally large macromolecular structure (> 40-mers) in solution. To investigate its unique multimerization feature, we determined the first crystal structures of Tk-AMPpase, in the apo-form and in complex with substrates. Structures of two truncated forms of Tk-AMPpase (Tk-AMPpaseΔN84 and Tk-AMPpaseΔC10) clarified that this multimerization is achieved by two dimer interfaces within a single molecule: one by the central domain and the other by the C-terminal domain, which consists of an unexpected domain-swapping interaction. The N-terminal domain, characteristic of archaeal enzymes, is essential for enzymatic activity, participating in multimerization as well as domain closure of the active site upon substrate binding. Moreover, biochemical analysis demonstrated that the macromolecular assembly of Tk-AMPpase contributes to its high thermostability, essential for an enzyme from a hyperthermophile. Our findings unveil a unique archaeal nucleotide phosphorylase that is distinct in both function and structure from previously known members of the nucleoside phosphorylase II family.
KW - archaea crystal
KW - assembly nucleotide
KW - metabolism phosphorylase
KW - structure multimeric
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U2 - 10.1016/j.jmb.2013.04.026
DO - 10.1016/j.jmb.2013.04.026
M3 - Article
C2 - 23659790
AN - SCOPUS:84879912039
SN - 0022-2836
VL - 425
SP - 2709
EP - 2721
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 15
ER -