3QIA: Crystal structure of P-loop G237A mutant of subunit A of the A1AO ATP synthase

The phosphate binding loop (GXXXXGKT(S)) is conserved in several mononucleotide-binding proteins with similar three-dimensional structures. Although variations in other amino acids have been noted, the first glycine and glycine-lysine residues are highly conserved in all enzymes, whose role is yet to be understood. Alanine substitutions for critically positioned glycines-G234, G237, and G239-were generated for the catalytic A-subunit of A-ATP synthase from Pyrococcus horikoshii OT3, and their crystal structures were determined. They showed altered conformation for the phosphate binding loop, with G234A and G237A becoming flat and with G239A taking an intermediate conformation, resulting in the active-site region being closed to nucleotide entry. Furthermore, the essential amino acids S238 and K240, which normally interact with the nucleotide, become inaccessible. These mutant structures demonstrate the role of the strictly conserved glycine residues in guarding the active-site region for nucleotide entrance in archaea-type ATP synthases.
PDB ID: 3QIADownload
MMDB ID: 94035
PDB Deposition Date: 2011/1/26
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 2.6  Å
Source Organism:
Similar Structures:
Biological Unit for 3QIA: monomeric; determined by author and by software (PISA)
Molecular Components in 3QIA
Label Count Molecule
Protein (1 molecule)
V-type ATP Synthase Alpha Chain(Gene symbol: PH_RS09340)
Molecule annotation
Chemicals (12 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB