PDBsum entry 2vu8

Hydrolase/inhibitor

PDB id: 2vu8

Contents

Protein chains

224 a.a. *

33 a.a. *

Waters ×191

* Residue conservation analysis

PDB id:

2vu8

Name:

Hydrolase/inhibitor

Title:

Crystal structure of an insect inhibitor with a fungal trypsin

Structure:

Trypsin. Chain: e. Fragment: peptidase s1, residues 25-248. Engineered: yes. Pacifastin-related serine protease inhibitor. Chain: i. Fragment: residues 25-57. Synonym: lmpi-3. Engineered: yes

Source:

Fusarium oxysporum. Mold. Organism_taxid: 5507. Expressed in: saccharomyces cerevisiae. Expression_system_taxid: 4932. Synthetic: yes. Locusta migratoria. Locust. Organism_taxid: 7004

Resolution:

1.80Å R-factor: 0.200 R-free: 0.241

Authors:

P.Leone,A.Roussel,C.Kellenberger

Key ref:

P.Leone et al. (2008). Structure of Locusta migratoria protease inhibitor 3 (LMPI-3) in complex with Fusarium oxysporum trypsin. Acta Crystallogr D Biol Crystallogr, 64, 1165-1171. PubMed id: 19020355 DOI: 10.1107/S0907444908030400

Date:

21-May-08 Release date: 23-Dec-08

Protein chain

P35049  (TRYP_FUSOX) -  Trypsin from Fusarium oxysporum

Seq: 248 a.a.

Struc: 224 a.a.

Protein chain

Q8WQ22  (Q8WQ22_LOCMI) -  Protease inhibitor from Locusta migratoria migratorioides

Seq: 145 a.a.

Struc: 33 a.a.

Enzyme reactions

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

DOI no: 10.1107/S0907444908030400

Acta Crystallogr D Biol Crystallogr 64:1165-1171 (2008)

PubMed id: 19020355

Structure of Locusta migratoria protease inhibitor 3 (LMPI-3) in complex with Fusarium oxysporum trypsin.

P.Leone, A.Roussel, C.Kellenberger.

ABSTRACT

Previous studies have shown that the trypsin inhibitors LMPI-1, LMPI-3 and SGTI from locusts display an unusual species selectivity. They inhibit locust, crayfish and fungal trypsins several orders of magnitude more efficiently than bovine trypsin. In contrast, the chymotrypsin inhibitors from the same family, LMPI-2 and SGCI, are active towards mammalian enzymes. The crystal structures of a variant of LMPI-1 and of LMPI-2 in complex with bovine chymotrypsin have revealed subtle structural differences between the trypsin and chymotrypsin inhibitors. In a previous report, it was proposed that Pro173 of bovine trypsin is responsible for the weak inhibitory activity of LMPI-1 and LMPI-3. A fungal trypsin from Fusarium oxysporum contains Gly173 instead of Pro173 and has been shown to be strongly inhibited by LMPI-1 and LMPI-3. To explore the structural features that are responsible for this property, the crystal structure of the complex between LMPI-3 and F. oxysporum trypsin was determined at 1.8 A resolution. This study indicates that this small inhibitor interacts with the protease through the reactive site P3-P4' and the P10-P6 residues. Comparison of this complex with the SGTI-crayfish trypsin and BPTI-bovine trypsin complexes reinforces this hypothesis on the role of residue 173 of trypsin in species selectivity.

Selected figure(s)

Figure 3.
Figure 3 (a) General overview of the complex between trypsin from F. oxysporum and LMPI-3 from L. migratoria. The trypsin is represented as a ribbon diagram (coloured grey) and its surface is shown as half-transparent. Residue Gly173 is coloured red. The residues Asp189 (specificity pocket) and Ser195 (catalytic serine) are depicted as sticks and coloured cyan. The inhibitor LMPI-3 is in ribbon representation and is coloured green. The disulfide bridges of LMPI-3 are shown in orange. The residue Arg29 (P1) is depicted as sticks and coloured magenta. The figure was generated using PyMOL (DeLano, 2002[DeLano, W. L. (2002). The PyMOL Molecular Graphics System. http://www.pymol.org .]). (b) Interaction surfaces of F. oxysporum trypsin and of LMPI-3. The two partners of the complex are represented as grey molecular surfaces and the amino acids that are buried upon binding are labelled and are coloured cyan (trypsin) and magenta (inhibitor). This figure was generated using PyMOL.

Figure 4.
Figure 4 Comparison of the active-site environment between trypsins from F. oxysporum and from P. leptodactylus. The fungal trypsin is represented as a grey ribbon and its loops 37, 60 and 97 are coloured blue. The side chains of Asn37 and Tyr59C are represented as sticks, with the N atom in blue and the O atom in red. The loops 37, 60 and 97 of crayfish trypsin are represented as ribbons and coloured orange. The side chains of Phe37, Phe37C, Phe39 and Tyr60 are represented as sticks. The inhibitor LMPI-3 is shown as a green ribbon. The side chains of residues P1 (Arg29), P1' (Lys30), P4' (Arg33) and Thr18 are represented as sticks and coloured according to atom type, with C atoms in green.

The above figures are reprinted by permission from the IUCr: Acta Crystallogr D Biol Crystallogr (2008, 64, 1165-1171) copyright 2008.

Figures were selected by an automated process.