TY - JOUR
T1 - The catalytic transition state in ATP synthase
AU - Senior, Alan E.
AU - Weber, Joachim
AU - Nadanaciva, Sashi
N1 - Funding Information:
This work was supported by NIH grant GM25349 to AES.
PY - 2000
Y1 - 2000
N2 - The catalytic transition state of ATP synthase has been characterized and modeled by combined use of (1) Mg-ADP-fluoroaluminate, Mg-ADP-fluoroscandium, and corresponding Mg-IDP-fluorometals as transition-state analogs: (2) fluorescence signals of β-Trp331 and β-Trp148 as optical probes to assess formation of the transition state: (3) mutations of critical catalytic residues to determine side-chain ligands required to stabilize the transition state. Rate acceleration by positive catalytic site cooperativity is explained as due to mobility of α-Arg376, acting as an "arginine finger" residue, which interacts with nucleotide specifically at the transition state step of catalysis, not with Mg-ATP- or Mg-ADP-bound ground states. We speculate that formation and collapse of the transition state may engender catalytic site α/β subunit-interface conformational movement, which is linked to γ-subunit rotation.
AB - The catalytic transition state of ATP synthase has been characterized and modeled by combined use of (1) Mg-ADP-fluoroaluminate, Mg-ADP-fluoroscandium, and corresponding Mg-IDP-fluorometals as transition-state analogs: (2) fluorescence signals of β-Trp331 and β-Trp148 as optical probes to assess formation of the transition state: (3) mutations of critical catalytic residues to determine side-chain ligands required to stabilize the transition state. Rate acceleration by positive catalytic site cooperativity is explained as due to mobility of α-Arg376, acting as an "arginine finger" residue, which interacts with nucleotide specifically at the transition state step of catalysis, not with Mg-ATP- or Mg-ADP-bound ground states. We speculate that formation and collapse of the transition state may engender catalytic site α/β subunit-interface conformational movement, which is linked to γ-subunit rotation.
KW - ATP synthase
KW - Catalytic transition state
KW - F-ATPase
KW - Oxidative phosphorylation
UR - http://www.scopus.com/inward/record.url?scp=0034466409&partnerID=8YFLogxK
U2 - 10.1023/A:1005625326721
DO - 10.1023/A:1005625326721
M3 - Article
C2 - 15254388
AN - SCOPUS:0034466409
SN - 0145-479X
VL - 32
SP - 523
EP - 530
JO - Journal of Bioenergetics and Biomembranes
JF - Journal of Bioenergetics and Biomembranes
IS - 5
ER -