Walker motifs
（重定向自Phosphate transport proteins）
![Alignment of the H-Ras mutant A59G mutants in complex with GppNHp (green cartoon) and GDP (cyan cartoon). The P-loop main chain is shown in red, the Mg2+ ion as green sphere and the side chains of the amino acids K16 and S17 are shown as sticks.](/Images/godic/202502/02/Ras-P-loop4239.png")
The Walker A and Walker B motifs are protein sequence motifs, now known to have highly conserved three-dimensional structures. These were first reported in ATP-binding proteins by Walker and co-workers in 1982.