PDBsum entry 1wlc

Sugar binding protein

PDB id: 1wlc

Contents

Protein chain

134 a.a. *

Ligands

MES

Waters ×93

* Residue conservation analysis

PDB id:

1wlc

Name:

Sugar binding protein

Title:

Congerin ii y16s/t88i double mutant

Structure:

Congerin ii. Chain: a. Synonym: beta-galactoside-binding lectin 2. Engineered: yes. Mutation: yes

Source:

Conger myriaster. Whitespotted conger. Organism_taxid: 7943. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

2.00Å R-factor: 0.182 R-free: 0.223

Authors:

C.Shionyu-Mitsuyama,Y.Ito,A.Konno,Y.Miwa,T.Ogawa,K.Muramoto,T.Shirai

Key ref:

C.Shionyu-Mitsuyama et al. (2005). In vitro evolutionary thermostabilization of congerin II: a limited reproduction of natural protein evolution by artificial selection pressure. J Mol Biol, 347, 385-397. PubMed id: 15740748 DOI: 10.1016/j.jmb.2005.01.027

Date:

22-Jun-04 Release date: 07-Jun-05

Protein chain

Q9YIC2  (LEG2_CONMY) -  Congerin-2 from Conger myriaster

Seq: 136 a.a.

Struc: 134 a.a.*

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

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1016/j.jmb.2005.01.027

J Mol Biol 347:385-397 (2005)

PubMed id: 15740748

In vitro evolutionary thermostabilization of congerin II: a limited reproduction of natural protein evolution by artificial selection pressure.

C.Shionyu-Mitsuyama, Y.Ito, A.Konno, Y.Miwa, T.Ogawa, K.Muramoto, T.Shirai.

ABSTRACT

The thermostability of the conger eel galectin, congerin II, was improved by in vitro evolutionary protein engineering. Two rounds of random PCR mutagenesis and selection experiments increased the congerin II thermostability to a level comparative to its naturally thermostable isoform, congerin I. The crystal structures of the most thermostable double mutant, Y16S/T88I, and the related single mutants, Y16S and T88I, were determined at 2.0 angstroms, 1.8 angstroms, and 1.6 angstroms resolution, respectively. The exclusion of two interior water molecules by the Thr88Ile mutation, and the relief of adjacent conformational stress by the Tyr16Ser mutation were the major contributions to the thermostability. These features in the congerin II mutants are similar to those observed in congerin I. The natural evolution of congerin genes, with the K(A)/K(S) ratio of 2.6, was accelerated under natural selection pressures. The thermostabilizing selection pressure artificially applied to congerin II mimicked the implied natural pressure on congerin I. The results showed that the artificial pressure made congerin II partially reproduce the natural evolution of congerin I.

Selected figure(s)

Figure 5.
Figure 5. (a) Comparison of the congerin II wild-type (gray) and mutant ConII-T88I (green) structures around the mutation site T88I. The water molecules expelled by the mutation Thr88Ile are represented by red spheres. H-bonds are shown in yellow. (b) Comparison of the congerin II wild-type (gray) and mutant ConII-Y16S (green) structures around the mutation site Y16S. Bound water molecules are shown by spheres. The H-bonds in the wild-type and mutant structures are shown in yellow and blue, respectively. The asterisk (*)marks the position of the loop connecting the S1-F2 strands.

Figure 6.
Figure 6. Comparison of the structures around the mutation sites of ConII-Y16S/T88I (green) with wild-type congerin I (blue). (a) Structures around the mutation site T88I. (b) Structures around the mutation site Y16S. The side-chains in wild-type congerin II are also superposed (gray).

The above figures are reprinted by permission from Elsevier: J Mol Biol (2005, 347, 385-397) copyright 2005.

Figures were selected by an automated process.