4GUX: Trypsin:MCoTi-II complex

Crystal structure of trypsin:MCoTi-II complex. Determined by X-ray diffraction at 1.8 Å resolution. Released 4 Sept 2013.

Method: X-ray diffraction
Resolution: 1.8 Å
Organisms: Bos taurus, Momordica cochinchinensis
Chains: 6
Atoms: 6,909
Mol. weight: 88.11 kDa
Ligands: CA
Released: 4 Sept 2013

Explore 4GUX in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

4GUX contains 24 α-helices and 73 β-strands across 6 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: 7 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	22	1	1
β-strand	25-26	2	2
β-strand	35-39	5	3
β-strand	43-51	9	3
β-strand	54-57	4	3
α-helix	59-61	3
β-strand	67-70	4	3
β-strand	83-92	10	3
β-strand	106-110	5	3
β-strand	124	1	2
α-helix	125-126	2
α-helix	129-131	3
β-strand	135-140	6	2
β-strand	156-162	7	2
α-helix	163-164	2
α-helix	165-171	7
β-strand	180-183	4	2
β-strand	191	1	1
β-strand	200-203	4	2
β-strand	206-214	9	2
β-strand	219	1	4
β-strand	222	1	4
β-strand	224-228	5	2
α-helix	229-232	4
α-helix	233-241	9

Chain B: 7 helices, 20 β-strands

Element	Residues	Length	Sheet
β-strand	22	1	5
β-strand	25-26	2	2
β-strand	35-39	5	6
β-strand	43-49	7	6
β-strand	54-57	4	6
α-helix	59-61	3
β-strand	67-70	4	6
β-strand	83-92	10	6
β-strand	106-110	5	6
β-strand	117	1	7
β-strand	120	1	7
β-strand	124	1	2
α-helix	125-126	2
α-helix	129-131	3
β-strand	135-140	6	2
β-strand	156-162	7	2
α-helix	163-164	2
α-helix	165-171	7
β-strand	180-183	4	2
β-strand	191	1	5
β-strand	200-203	4	2
β-strand	206-214	9	2
β-strand	219	1	8
β-strand	222	1	8
β-strand	224-228	5	2
α-helix	229-231	3
α-helix	233-242	10

Chain C: 7 helices, 20 β-strands

Element	Residues	Length	Sheet
β-strand	22	1	9
β-strand	25-26	2	10
β-strand	35-39	5	11
β-strand	43-51	9	11
β-strand	54-57	4	11
α-helix	59-61	3
β-strand	67-70	4	11
β-strand	83-92	10	11
β-strand	106-110	5	11
β-strand	117	1	12
β-strand	120	1	12
β-strand	124	1	10
α-helix	125-126	2
α-helix	129-131	3
β-strand	135-140	6	10
β-strand	156-162	7	10
α-helix	163-164	2
α-helix	165-171	7
β-strand	180-183	4	10
β-strand	191	1	9
β-strand	200-203	4	10
β-strand	206-214	9	10
β-strand	219	1	13
β-strand	222	1	13
β-strand	224-228	5	10
α-helix	229-231	3
α-helix	233-242	10

Chains D, E and F: 1 helix, 5 β-strands

Element	Residues	Length	Sheet
β-strand	8-9	2	2
β-strand	14	1	14
α-helix	18-20	3
β-strand	27	1	15
β-strand	32	1	14
β-strand	33	1	15

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Cationic trypsin	A, B, C	protein	246	Bos taurus	P00760 (AlphaFold model)
Trypsin inhibitor 2	D, E, F	protein	34	Momordica cochinchinensis	P82409 (AlphaFold model)

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

>4GUX_1 Cationic trypsin (chains A, B, C)
MKTFIFLALLGAAVAFPVDDDDKIVGGYTCGANTVPYQVSLNSGYHFCGGSLINSQWVVS
AAHCYKSGIQVRLGEDNINVVEGNEQFISASKSIVHPSYNSNTLNNDIMLIKLKSAASLN
SRVASISLPTSCASAGTQCLISGWGNTKSSGTSYPDVLKCLKAPILSDSSCKSAYPGQIT
SNMFCAGYLEGGKDSCQGDSGGPVVCSGKLQGIVSWGSGCAQKNKPGVYTKVCNYVSWIK
QTIASN

Sequence of entity 2 (D, E, F), FASTA

>4GUX_2 Trypsin inhibitor 2 (chains D, E, F)
SGSDGGVCPKILKKCRRDSDCPGACICRGNGYCG

Ligands and cofactors

ID	Name	Formula	Copies
CA	Calcium ion	Ca	3

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

Primary citation

Structural insights into the role of the cyclic backbone in a squash trypsin inhibitor. Daly, N.L., Thorstholm, L., Greenwood, K.P. et al. J Biol Chem (2013) 288:36141-36148. DOI 10.1074/jbc.M113.528240 · PubMed

Other PDB entries of the same protein (UniProt P00760 (AlphaFold model), which also has an AlphaFold model), best resolution first:

4I8H 0.75 Å, Bovine trypsin at 0.75 resolution
5MN1 0.79 Å, Cationic trypsin in complex with 2-aminopyridine (deuterated sample at 100 K)
5MNK 0.8 Å, Cationic trypsin in complex with benzylamine (deuterated sample at 100 K)
3MFJ 0.8 Å, Bovine trypsin at 0.8 A resolution, restrained refinement
3MI4 0.8 Å, Bovine trypsin at 0.8 A resolution, non-restrained refinement
4I8G 0.8 Å, Bovine trypsin at 0.8 resolution
4I8K 0.85 Å, Bovine trypsin at 0.85 resolution
5MNN 0.86 Å, Cationic trypsin in complex with N-amidinopiperidine (deuterated sample at 100 K)
5MNG 0.86 Å, Cationic trypsin in complex with benzamidine (deuterated sample at 100 K)
4I8J 0.87 Å, Bovine trypsin at 0.87 A resolution
4I8L 0.87 Å, Bovine trypsin at 0.87 resolution
4XOJ 0.91 Å, Structure of bovine trypsin in complex with analogues of sunflower inhibitor 1 (SFTI-1)

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