1QQR: Streptokinase domain B

Crystal structure of streptokinase domain B. Determined by X-ray diffraction at 2.3 Å resolution. Released 17 Jun 1999.

Method: X-ray diffraction
Resolution: 2.3 Å
Organism: Streptococcus dysgalactiae subsp. equisimilis
Chains: 4
Atoms: 4,794
Mol. weight: 64.09 kDa
Released: 17 Jun 1999

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

Secondary structure: helices and β-sheets

1QQR contains 11 α-helices and 46 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: 2 helices, 12 β-strands

Element	Residues	Length	Sheet
β-strand	154	1	1
β-strand	158-168	11	2
β-strand	179	1	3
β-strand	183-188	6	2
β-strand	193-195	3	4
α-helix	196-210	15
β-strand	214-226	13	2
β-strand	233-234	2	2
β-strand	242-244	3	4
β-strand	249	1	1
α-helix	250-251	2
β-strand	252-254	3	5
β-strand	261-263	3	5
β-strand	266-278	13	2

Chain B: 3 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	154	1	6
β-strand	158-168	11	7
β-strand	183-188	6	7
β-strand	193-195	3	8
α-helix	196-210	15
β-strand	214-226	13	7
β-strand	233-234	2	7
α-helix	235-236	2
β-strand	242-244	3	8
β-strand	249	1	6
α-helix	250-251	2
β-strand	252-254	3	9
β-strand	261-263	3	9
β-strand	266-278	13	7

Chain C: 3 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	154	1	10
β-strand	158-168	11	11
β-strand	183-188	6	11
β-strand	193-195	3	12
α-helix	196-210	15
β-strand	214-226	13	11
β-strand	233-235	3	11
α-helix	236	1
β-strand	242-244	3	12
β-strand	249	1	10
α-helix	250-251	2
β-strand	252-254	3	13
β-strand	261-263	3	13
β-strand	266-278	13	11

Chain D: 3 helices, 12 β-strands

Element	Residues	Length	Sheet
β-strand	154	1	14
β-strand	158-168	11	15
β-strand	179	1	5
β-strand	183-188	6	15
β-strand	193-195	3	16
α-helix	196-210	15
β-strand	214-226	13	15
β-strand	233-234	2	15
β-strand	242-244	3	16
β-strand	249	1	14
α-helix	250-251	2
β-strand	252-254	3	3
β-strand	261-263	3	3
β-strand	266-278	13	15
α-helix	285-287	3

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Streptokinase domain B	A, B, C, D	protein	138	Streptococcus dysgalactiae subsp. equisimilis	P00779 (AlphaFold model)

Sequence of entity 1 (A, B, C, D), FASTA

>1QQR_1 STREPTOKINASE DOMAIN B (chains A, B, C, D)
IQNQAKSVDVEYTVQFTPLNPDDDFRPGLKLTKLLKTLAIGDTITSQELLAQAQSILNKN
HPGYTIYERDSSIVTHDNDIFRTILPMDQEFTYRVKNREQAYRINKKSGLNEEINNTDLI
SEKYYVLKKGEKPYDPFD

Primary citation

Crystal Structure of Streptokinse Domain B. Spraggon, G., Zhang, X.X., Ponting, C.P. et al. To be published.

Other PDB entries of the same protein (UniProt P00779 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1L4D 2.3 Å, Crystal structure of microplasminogen-streptokinase alpha domain complex
1L4Z 2.8 Å, X-ray crystal structure of the complex of microplasminogen with alpha domain of…
1BML 2.9 Å, Complex of the catalytic domain of human plasmin and streptokinase

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