PDBsum entry 1mcu

Hydrolase/hydrolase inhibitor

PDB id: 1mcu

Contents

Protein chains

222 a.a.

28 a.a.

Metals

_CA

Waters ×166

Superseded by:

1f2s

PDB id:

1mcu

Name:

Hydrolase/hydrolase inhibitor

Title:

Crystal structure of the complex formed between bovine beta- trypsin and mcti-a, a trypsin inhibitor of squash family at 1.8a resolution

Structure:

Trypsin. Chain: e. Engineered: yes. Trypsin inhibitor a. Chain: i

Source:

Bos taurus. Bovine. Organ: pancreatic. Expressed in: e.Coli. Momordica charantia. Bitter gourd seeds

Biol. unit:

Dimer (from PQS)

Resolution:

1.80Å R-factor: 0.185 R-free: 0.222

Authors:

Q.Huang,Y.Zhuy,Y.Tang

Key ref:

Y.Zhu et al. (1999). Crystal structure of the complex formed between bovine beta-trypsin and MCTI-A, a trypsin inhibitor of squash family, at 1.8-A resolution. J Protein Chem, 18, 505-509. PubMed id: 10524768

Date:

05-May-99 Release date: 20-May-99

Protein chain

P00760  (TRY1_BOVIN) -  Cationic trypsin

Seq: 246 a.a.

Struc: 222 a.a.

Protein chain

P10295  (ITR2_MOMCH) -  Trypsin inhibitor 2

Seq: 28 a.a.

Struc: 28 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: Chain E: E.C.3.4.21.4 - trypsin.
• Reaction: Preferential cleavage: Arg-|-Xaa, Lys-|-Xaa.

J Protein Chem 18:505-509 (1999)

PubMed id: 10524768

Crystal structure of the complex formed between bovine beta-trypsin and MCTI-A, a trypsin inhibitor of squash family, at 1.8-A resolution.

Y.Zhu, Q.Huang, M.Qian, Y.Jia, Y.Tang.

ABSTRACT

The stoichiometric complex formed between bovine beta-trypsin and Momordica charantia, Linn. Cucurbitaceae trypsin inhibitor A (MCTI-A) was crystallized and its X-ray crystal structure was refined to a final R value of 0.179 using data of 7.0- to 1.8-A resolution. Combination with results on the complex of MCTI-A with porcine trypsin gives the sequence of MCTI-A definitely, of which 13 residues are conserved compared with other squash family trypsin inhibitors. Its spatial structure and the conformation of its primary binding segment from Cys3I (P3) to Glu7I (P3'), which contains a reactive scissile bond Arg5I C-Ile6I N, were found to be very similar to the other squash family proteinase inhibitors.