1RTK: Complement factor B Bb fragment

Crystal Structure Analysis of the Bb segment of Factor B complexed with 4-guanidinobenzoic acid. Determined by X-ray diffraction at 2.3 Å resolution. Released 14 Dec 2004.

Method: X-ray diffraction
Resolution: 2.3 Å
Organism: Homo sapiens
Chains: 1
Atoms: 4,063
Mol. weight: 56.86 kDa
Ligands: MG, GBS
Released: 14 Dec 2004

Explore 1RTK in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1RTK contains 25 α-helices and 23 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: 25 helices, 23 β-strands

Element	Residues	Length	Sheet
β-strand	244-251	8	1
α-helix	258-277	20
β-strand	283-289	7	1
β-strand	293-297	5	1
α-helix	302-305	4
α-helix	307-316	10
α-helix	319-321	3
α-helix	330-341	12
α-helix	352-354	3
β-strand	356-363	8	1
α-helix	374-383	10
α-helix	395-397	3
β-strand	398-404	7	1
α-helix	411-417	7
β-strand	427-429	3	1
α-helix	433-443	11
α-helix	446-449	4
α-helix	464-467	4
β-strand	471-476	6	2
β-strand	484-490	7	2
β-strand	495-498	4	2
α-helix	500-502	3
α-helix	509-511	3
β-strand	512-516	5	2
β-strand	523-530	8	2
α-helix	540-542	3
β-strand	553-557	5	2
β-strand	564	1	3
β-strand	567	1	3
α-helix	569-570	2
β-strand	571	1	4
β-strand	575	1	5
α-helix	576-581	6
α-helix	590-597	8
β-strand	602-611	10	4
β-strand	614-623	10	4
α-helix	628-633	6
α-helix	634-637	4
α-helix	647-649	3
β-strand	655-659	5	4
α-helix	671-673	3
α-helix	676	1
β-strand	677-682	6	4
β-strand	685-695	11	4
β-strand	714-719	6	4
α-helix	720-723	4
α-helix	724-730	7
β-strand	738	1	5

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Complement factor B Bb fragment	A	protein	497	Homo sapiens	P00751 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>1RTK_1 Complement factor B Bb fragment (chains A)
SMNIYLVLDGSDSIGASNFTGAKKVLVNLIEKVASYGVKPRYGLVTYATYPKIWVKVSEA
DSSNADWVTKQLNEINYEDHKLKSGTNTKKALQAVYSMMSWPDDVPPEGWNRTRHVIILM
TDGLHNMGGDPITVIDEIRDLLYIGKDRKNPREDYLDVYVFGVGPLVNQVNINALASKKD
NEQHVCKVKDMECLEDVFYQMIDESQSLSLCGMVWEHRKGTDYHKQPWQAKISVIRPSKG
HESCMGAVVSEYFVLTAAHCFTVDDKEHSIKVSVGGEKRDLEIEVVLFHPNYNINGKKEA
GIPEFYDYDVALIKLKNKLKYGQTIRPICLPCTEGTTRALRLPPTTTCQQQKEELLPAQD
IKALFVSEEEKKLTRKEVYIKNGDKKGSCERDAQYAPGYDKVKDISEVVTPRFLCTGGVS
PYADPNTCRGDSGGPLIVHKRSRFIQVGVISWGVVDVCKNQKRQKQVPAHARDFHINLFQ
VLPWLKEKLQDEDLGFL

Ligands and cofactors

ID	Name	Formula	Copies
MG	Magnesium ion	Mg	1
GBS	4-carbamimidamidobenzoic acid	C8 H9 N3 O2	1

Water and common crystallization additives (IOD, NA) are not listed.

Primary citation

Structural analysis of engineered Bb fragment of complement factor B: insights into the activation mechanism of the alternative pathway C3-convertase. Ponnuraj, K., Xu, Y., Macon, K. et al. Mol Cell (2004) 14:17-28. DOI 10.1016/S1097-2765(04)00160-1 · PubMed

Other PDB entries of the same protein (UniProt P00751 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6QSW 1.64 Å, Complement factor B protease domain in complex with the reversible inhibitor…
6RAV 1.7 Å, Complement factor B protease domain in complex with the reversible inhibitor…
6T8W 1.7 Å, Complement factor B in complex with (-)-4-(1-((5,7-Dimethyl-1H-indol-4-yl)methyl)piperidi…
6QSX 1.77 Å, Complement factor B protease domain in complex with the reversible inhibitor…
1Q0P 1.8 Å, A domain of Factor B
1RRK 2.0 Å, Crystal Structure Analysis of the Bb segment of Factor B
1DLE 2.1 Å, Factor B serine protease domain
3HRZ 2.2 Å, Cobra Venom Factor (CVF) in complex with human factor B
6T8V 2.29 Å, Complement factor B in complex with (S)-5,7-Dimethyl-4-((2-phenylpiperidin-1-yl)methyl)-1…
2OK5 2.3 Å, Human Complement factor B
1RS0 2.6 Å, Crystal Structure Analysis of the Bb segment of Factor B complexed with…
9U62 2.7 Å, AP pathways C3 convertase C3bBbP and C3 complex

Browse structure collections

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