1A3B: Alpha-thrombin

Complex of human alpha-thrombin with the bifunctional boronate inhibitor BOROLOG1. Determined by X-ray diffraction at 1.8 Å resolution. Released 3 Jun 1998.

Method: X-ray diffraction
Resolution: 1.8 Å
Organisms: Homo sapiens, Hirudo medicinalis
Chains: 3
Atoms: 2,606
Mol. weight: 36.41 kDa
Ligands: T29
Released: 3 Jun 1998

Explore 1A3B in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1A3B contains 14 α-helices and 22 β-strands across 3 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 H: 11 helices, 22 β-strands

Element	Residues	Length	Sheet
β-strand	17	1	1
β-strand	20-21	2	2
α-helix	22-23	2
β-strand	30-35	6	3
β-strand	39-46	8	3
β-strand	51-54	4	3
α-helix	56-58	3
β-strand	60-60A	2	4
α-helix	60B-60D	3
β-strand	60F-60G	2	4
α-helix	61-63	3
β-strand	64-68	5	3
β-strand	72	1	5
β-strand	81-90	10	3
β-strand	95	1	6
β-strand	100	1	6
β-strand	104-108	5	3
α-helix	111-114	4
α-helix	120-121	2
β-strand	122	1	2
α-helix	126-129C	7
β-strand	135-140	6	2
β-strand	154	1	5
β-strand	156-162	7	2
α-helix	165-169	5
β-strand	180-183	4	2
α-helix	186-186B	3
β-strand	189	1	1
β-strand	198-202	5	2
β-strand	207-215	9	2
β-strand	226-230	5	2
α-helix	232-234	3
α-helix	235-244	10

Chain I: 1 helix, 0 β-strands

Element	Residues	Length	Sheet
α-helix	12-15	4

Chain L: 2 helices, 0 β-strands

Element	Residues	Length	Sheet
α-helix	8-10	3
α-helix	14C-14G	5

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Alpha-thrombin (small subunit)	L	protein	36	Homo sapiens	P00734 (AlphaFold model)
Alpha-thrombin (large subunit)	H	protein	259	Homo sapiens	P00734 (AlphaFold model)
Hirudin	I	protein	18	Hirudo medicinalis	P28504 (AlphaFold model)

Sequence of entity 1 (L), FASTA

>1A3B_1 ALPHA-THROMBIN (SMALL SUBUNIT) (chains L)
TFGSGEADCGLRPLFEKKSLEDKTERELLESYIDGR

Sequence of entity 2 (H), FASTA

>1A3B_2 ALPHA-THROMBIN (LARGE SUBUNIT) (chains H)
IVEGSDAEIGMSPWQVMLFRKSPQELLCGASLISDRWVLTAAHCLLYPPWDKNFTENDLL
VRIGKHSRTRYERNIEKISMLEKIYIHPRYNWRENLDRDIALMKLKKPVAFSDYIHPVCL
PDRETAASLLQAGYKGRVTGWGNLKETWTANVGKGQPSVLQVVNLPIVERPVCKDSTRIR
ITDNMFCAGYKPDEGKRGDACEGDSGGPFVMKSPFNNRWYQMGIVSWGEGCDRDGKYGFY
THVFRLKKWIQKVIDQFGE

Sequence of entity 3 (I), FASTA

>1A3B_3 Hirudin (chains I)
GGQSHNDGDFEEIPEEYL

Ligands and cofactors

ID	Name	Formula	Copies
T29	TRI166 (bifunctional boronate inhibitor)	C22 H34 B N5 O5 S	1

Primary citation

Bifunctional peptide boronate inhibitors of thrombin: crystallographic analysis of inhibition enhanced by linkage to an exosite 1 binding peptide. Skordalakes, E., Elgendy, S., Goodwin, C.A. et al. Biochemistry (1998) 37:14420-14427. DOI 10.1021/bi980225a · PubMed

Other PDB entries of the same protein (UniProt P00734 (AlphaFold model), which also has an AlphaFold model), best resolution first:

5AFY 1.12 Å, Thrombin in complex with 3-chloro-benzamide
4UD9 1.12 Å, Thrombin in complex with 5-chlorothiophene-2-carboxamide
4UE7 1.13 Å, Thrombin in complex with 1-amidinopiperidine
4UDW 1.16 Å, Thrombin in complex with 1-(2R)-2-amino-3-phenyl-propanoyl-N-(2,…
4UEH 1.16 Å, Thrombin in complex with benzamidine
5AF9 1.18 Å, Thrombin in complex with 4-Methoxy-N-(2-pyridinyl)benzamide
3RM2 1.23 Å, Human Thrombin in complex with MI003
5AHG 1.24 Å, Thrombin in complex with ((4-chlorophenyl)sulfamoyl))diemethylamine
2BVR 1.25 Å, Human thrombin complexed with fragment-based small molecules occupying the S1 pocket
3VXE 1.25 Å, Human alpha-thrombin-Bivalirudin complex at PD5.0
2UUF 1.26 Å, Thrombin-hirugen binary complex at 1.26A resolution
3SI4 1.27 Å, Human Thrombin In Complex With UBTHR104

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