12XE: KRAS(Q61K)

Crystal structure of KRAS(Q61K) bound to GppNHp and ligand. Determined by X-ray diffraction at 1.01 Å resolution. Released 26 Aug 2026.

Method: X-ray diffraction
Resolution: 1.01 Å
Organism: Homo sapiens
Chains: 1
Atoms: 1,597
Mol. weight: 20.66 kDa
Ligands: MG, GNP, A1DEM
Released: 26 Aug 2026

Explore 12XE in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

12XE contains 7 α-helices and 6 β-strands across 1 chain. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 7 helices, 6 β-strands

Element	Residues	Length	Sheet
α-helix	1	1
β-strand	2-10	9	1
α-helix	16-25	10
β-strand	38-46	9	1
β-strand	49-57	9	1
α-helix	66-73	8
β-strand	77-83	7	1
α-helix	87-91	5
α-helix	93-104	12
β-strand	111-116	6	1
α-helix	127-137	11
β-strand	141-143	3	1
α-helix	152-167	16

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Isoform 2B of GTPase KRas	A	protein	170	Homo sapiens	P01116 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>12XE_1 Isoform 2B of GTPase KRas (chains A)
GMTEYKLVVVGAGGVGKSALTIQLIQNHFVDEYDPTIEDSYRKQVVIDGETCLLDILDTA
GKEEYSAMRDQYMRTGEGFLCVFAINNTKSFEDIHHYREQIKRVKDSEDVPMVLVGNKCD
LPSRTVDTKQAQDLARSYGIPFIETSAKTRQGVDDAFYTLVREIRKHKEK

Ligands and cofactors

ID	Name	Formula	Copies
MG	Magnesium ion	Mg	1
GNP	Phosphoaminophosphonic acid-guanylate ester	C10 H17 N6 O13 P3	1
A1DEM	(4P)-5-ethynyl-6-fluoro-4-(8-fluoro-2-{[(2R,4R,7aS)-2-fluorotetrahydro-1H-pyrro…	C38 H37 F3 N8 O2	1

Water and common crystallization additives (GOL) are not listed.

Primary citation

Bronsted-basic small molecules activate GTP hydrolysis in KRAS-Q61 mutants. Wang, Y.C., Chen, S.C., Cao, Y. et al. Nat Chem Biol (2026). DOI 10.1038/s41589-026-02291-1 · PubMed

Other PDB entries of the same protein (UniProt P01116 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9IAY 0.95 Å, Structure of 10 in complex with GDP-KRAS
9IAW 1.0 Å, Structure of 5 in complex with GDP-KRAS
8ONV 1.01 Å, KRAS-G13D in complex with BI-2493
6P0Z 1.01 Å, Crystal structure of N-acetylated KRAS (2-169) bound to GDP and Mg
9IB5 1.01 Å, Structure of 18 (BI-2493) in complex with GDP-KRAS
8AZZ 1.02 Å, KRAS-G12V in complex with BI-2865
8AZX 1.04 Å, KRAS-G12C in complex with BI-2865
8B00 1.04 Å, KRAS-G13D in complex with BI-2865
8TVK 1.04 Å, KRAS 1-169 G12C Mutant at 100k
4QL3 1.04 Å, Crystal Structure of a GDP-bound G12R Oncogenic Mutant of Human GTPase KRas
8AZV 1.05 Å, KRAS in complex with BI-2865
9IB4 1.06 Å, Structure of 12 in complex with GDP-KRAS

Browse structure collections

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