P-loop

Introduction

The best conserved sequence of ATP/GTP binding motifs is a glycine-rich region, which forms a flexible loop between a beta-strand & an alpha-helix. This loop interacts with one of the phosphates of the nucleotide, thus the name 'P-loop'.

Not all ATP- or GTP-binding proteins seem to contain this motif.

More general terms

• ATP-binding site or Rossmann motif
• GTP-binding site