Role of αPhe-291 residue in the phosphate-binding subdomain of catalytic sites of Escherichia coli ATP synthase

2008 ◽  
Vol 471 (2) ◽  
pp. 168-175 ◽  
Author(s):  
Laura E. Brudecki ◽  
Johnny J. Grindstaff ◽  
Zulfiqar Ahmad
Keyword(s):  
Escherichia Coli ◽  
Atp Synthase ◽  
Phosphate Binding ◽  
Catalytic Sites

scholarly journals Role of Charged Residues in the Catalytic Sites of Escherichia coli ATP Synthase

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Zulfiqar Ahmad ◽  
Florence Okafor ◽  
Thomas F. Laughlin
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Atp Synthase ◽  
Electrostatic Interactions ◽  
Critical Role ◽  
Phosphate Binding ◽  
Catalytic Sites ◽  
Charged Residues ◽  
Positively Charged

Here we describe the role of charged amino acids at the catalytic sites of Escherichia coli ATP synthase. There are four positively charged and four negatively charged residues in the vicinity of of E. coli ATP synthase catalytic sites. Positive charges are contributed by three arginine and one lysine, while negative charges are contributed by two aspartic acid and two glutamic acid residues. Replacement of arginine with a neutral amino acid has been shown to abrogate phosphate binding, while restoration of phosphate binding has been accomplished by insertion of arginine at the same or a nearby location. The number and position of positive charges plays a critical role in the proper and efficient binding of phosphate. However, a cluster of many positive charges inhibits phosphate binding. Moreover, the presence of negatively charged residues seems a requisite for the proper orientation and functioning of positively charged residues in the catalytic sites. This implies that electrostatic interactions between amino acids are an important constituent of initial phosphate binding in the catalytic sites. Significant loss of function in growth and ATPase activity assays in mutants generated through charge modulations has demonstrated that precise location and stereochemical interactions are of paramount importance.

scholarly journals Role of βAsn-243 in the Phosphate-binding Subdomain of Catalytic Sites ofEscherichia coliF1-ATPase

2004 ◽  
Vol 279 (44) ◽  
pp. 46057-46064 ◽  
Author(s):  
Zulfiqar Ahmad ◽  
Alan E. Senior
Keyword(s):  
Atpase Activity ◽  
Atp Synthase ◽  
Catalytic Mechanism ◽  
Wild Type ◽  
Phosphate Binding ◽  
Γ Subunit ◽  
Catalytic Sites ◽  
The Face ◽  
Extensive Involvement

In the catalytic mechanism of ATP synthase, phosphate (Pi) binding and release steps are believed to be correlated to γ-subunit rotation, and Pibinding is proposed to be prerequisite for binding ADP in the face of high cellular [ATP]/[ADP] ratios. In x-ray structures, residue βAsn-243 appears centrally located in the Pi-binding subdomain of catalytic sites. Here we studied the role of βAsn-243 inEscherichia coliATP synthase by mutagenesis to Ala and Asp. Mutation βN243A caused 30-fold impairment of F1-ATPase activity; 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole inhibited this activity less potently than in wild type and Piprotected from inhibition. ADP-fluoroaluminate was more inhibitory than in wild-type, but ADP-fluoroscandium was less inhibitory. βN243D F1-ATPase activity was impaired by 1300-fold and was not inhibited by ADP-fluoroaluminate or ADP-fluoroscandium. 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole activated βN243D F1-ATPase, and Pidid not affect activation. We conclude that residue βAsn-243 is not involved in Pibinding directly but is necessary for correct organization of the transition state complex through extensive involvement in hydrogen bonding to neighboring residues. It is also probably involved in orientation of the “attacking water” and of an associated second water.

scholarly journals An alternative role of FoF1-ATP synthase in Escherichia coli: synthesis of thiamine triphosphate

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Tiziana Gigliobianco ◽  
Marjorie Gangolf ◽  
Bernard Lakaye ◽  
Bastien Pirson ◽  
Christoph von Ballmoos ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Atp Synthase ◽  
Thiamine Triphosphate ◽  
Fof1 Atp Synthase

scholarly journals Functional importance of αIle-346 and αIle-348 in the catalytic sites of Escherichia coli ATP synthase

2016 ◽  
Vol 592 ◽  
pp. 27-37 ◽  
Author(s):  
Chao Zhao ◽  
Hiba Syed ◽  
Sherif S. Hassan ◽  
Vineet K. Singh ◽  
Zulfiqar Ahmad
Keyword(s):  
Escherichia Coli ◽  
Atp Synthase ◽  
Functional Importance ◽  
Catalytic Sites
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