1G0M

CRYSTAL STRUCTURE OF T4 LYSOZYME MUTANT T152I

Summary for 1G0M

• Entry DOI: 10.2210/pdb1g0m/pdb
• Descriptor: PROTEIN (LYSOZYME), CHLORIDE ION, 2-HYDROXYETHYL DISULFIDE, ... (4 entities in total)
• Functional Keywords: hydrolase, o-glycosyl, glycosidase, bacteriolytic enzyme
• Biological source: Enterobacteria phage T4
• Cellular location: Host cytoplasm : P00720
• Total number of polymer chains: 1
• Total formula weight: 18865.58

Authors

Xu, J.,Baase, W.A.,Quillin, M.L.,Matthews, B.W. (deposition date: 2000-10-06, release date: 2001-05-23, Last modification date: 2024-02-07)

Primary citation

Xu, J.,Baase, W.A.,Quillin, M.L.,Baldwin, E.P.,Matthews, B.W.
Structural and thermodynamic analysis of the binding of solvent at internal sites in T4 lysozyme.
Protein Sci., 10:1067-1078, 2001

PubMed Abstract: To investigate the structural and thermodynamic basis of the binding of solvent at internal sites within proteins a number of mutations were constructed in T4 lysozyme. Some of these were designed to introduce new solvent-binding sites. Others were intended to displace solvent from preexisting sites. In one case Val-149 was replaced with alanine, serine, cysteine, threonine, isoleucine, and glycine. Crystallographic analysis shows that, with the exception of isoleucine, each of these substitutions results in the binding of solvent at a polar site that is sterically blocked in the wild-type enzyme. Mutations designed to perturb or displace a solvent molecule present in the native enzyme included the replacement of Thr-152 with alanine, serine, cysteine, valine, and isoleucine. Although the solvent molecule was moved in some cases by up to 1.7 A, in no case was it completely removed from the folded protein. The results suggest that hydrogen bonds from the protein to bound solvent are energy neutral. The binding of solvent to internal sites within proteins also appears to be energy neutral except insofar as the bound solvent may prevent a loss of energy due to potential hydrogen bonding groups that would otherwise be unsatisfied. The introduction of a solvent-binding site appears to require not only a cavity to accommodate the water molecule but also the presence of polar groups to help satisfy its hydrogen-bonding potential. It may be easier to design a site to accommodate two or more water molecules rather than one as the solvent molecules can then hydrogen-bond to each other. For similar reasons it is often difficult to design a point mutation that will displace a single solvent molecule from the core of a protein.

PubMed: 11316887
DOI: 10.1110/ps.02101

Experimental method

X-RAY DIFFRACTION (1.7 Å)