9HLL: Murine aM I-domain

murine aM I-domain in complex with nanobody aCR3. Determined by X-ray diffraction at 2.17 Å resolution. Released 17 Dec 2025.

Method: X-ray diffraction
Resolution: 2.17 Å
Organisms: Mus musculus, Lama glama
Chains: 4
Atoms: 4,407
Mol. weight: 65.98 kDa
Released: 17 Dec 2025

Explore 9HLL in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9HLL contains 19 α-helices and 41 β-strands across 4 chains. 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: 12 helices, 8 β-strands

Element	Residues	Length	Sheet
β-strand	149-156	8	1
α-helix	163-179	17
β-strand	185-192	8	1
β-strand	196-200	5	1
α-helix	202-207	6
α-helix	211-215	5
β-strand	225	1	2
α-helix	227-233	7
α-helix	234-238	5
α-helix	241-243	3
α-helix	245-246	2
β-strand	250-257	8	1
β-strand	262	1	2
α-helix	268-270	3
α-helix	272-277	6
β-strand	280-286	7	1
α-helix	294-303	10
α-helix	308-310	3
β-strand	312-314	3	1
α-helix	319-327	9

Chain B: 2 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	4-8	5	3
β-strand	11-14	4	4
β-strand	19-26	8	3
α-helix	30-32	3
β-strand	33-40	8	4
β-strand	47-52	6	4
β-strand	58-60	3	4
β-strand	68-73	6	3
β-strand	78-83	6	3
α-helix	88-90	3
β-strand	92-100	9	4
β-strand	112-113	2	4
β-strand	117-122	6	4

Chain C: 3 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	4-8	5	5
β-strand	11-14	4	6
β-strand	19-26	8	5
α-helix	30-32	3
β-strand	33-40	8	6
β-strand	47-53	7	6
β-strand	57-60	4	6
β-strand	68-73	6	5
β-strand	78-83	6	5
α-helix	88-90	3
β-strand	92-100	9	6
α-helix	101-103	3
β-strand	112-113	2	6
β-strand	117-122	6	6

Chain D: 2 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	4-8	5	7
β-strand	11-14	4	8
β-strand	19-26	8	7
α-helix	30-32	3
β-strand	33-40	8	8
β-strand	47-53	7	8
β-strand	57-60	4	8
β-strand	68-73	6	7
β-strand	78-83	6	7
α-helix	88-90	3
β-strand	92-100	9	8
β-strand	112-113	2	8
β-strand	117-122	6	8

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Integrin alpha-M	A	protein	198	Mus musculus	P05555 (AlphaFold model)
aCR3 nanobody	B, C, D	protein	130	Lama glama

Sequence of entity 1 (A), FASTA

>9HLL_1 Integrin alpha-M (chains A)
GAMESPQQESDIVFLIDGSGSINNIDFQKMKEFVSTVMEQFKKSKTLFSLMQYSDEFRIH
FTFNDFKRNPSPRSHVSPIKQLNGRTKTASGIRKVVRELFHKTNGARENAAKILVVITDG
EKFGDPLDYKDVIPEADRAGVIRYVIGVGNAFNKPQSRRELDTIASKPAGEHVFQVDNFE
ALNTIQNQLQEKGFAIEG

Sequence of entity 2 (B, C, D), FASTA

>9HLL_2 aCR3 nanobody (chains B, C, D)
QVQLVESGGGLVQAGGSLRLSCTTSGFTFDDYAIGWFRQAPGKEREGVSCISSSEGKYYS
DSAKGRFTISSDNAKNTVYLQMNNLKPEDTAVYYCAAEWNNFGRLCMYPDYWGQGTQVTV
SSLEHHHHHH

Primary citation

Three cryo-EM structures of complement C3d-bound alpha M beta 2 reveal an unexpected layer of dynamics for alpha I-containing integrin receptors. Lorentzen, J., Fruergaard, M.U., Lukacsi, S. et al. Sci Adv (2026) 12:eaea7241-eaea7241. DOI 10.1126/sciadv.aea7241 · PubMed

Other PDB entries of the same protein (UniProt P05555 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6RHV 2.29 Å, Crystal structure of mouse CD11b I-domain (CD11b-I) in complex with Staphylococcus…

Browse structure collections

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