Distributions of structural features contributing to thermostability in mesophilic and thermophilic K/L barrel glycosyl hydrolases
نویسندگان
چکیده
Analysis of the structural basis for thermostability in proteins has come mainly from pairwise comparisons of mesophilic and thermophilic structures and has often yielded conflicting results. Interpretation of these results would be enhanced by knowing the normal range of features found for mesophilic proteins. In order to provide the average and distribution values of structural features among similar mesophilic proteins, we compared the amino acid composition, solvent accessible surface area, hydrogen bonds, number of ion pairs, and thermal factors of 22 structures of K/L barrel glycosyl hydrolases. These distributions are then compared to values from seven K/L barrel glycosyl hydrolases from thermophilic organisms. We find that the distribution of each structural feature is broad within the mesophilic proteins and illustrates the difficulty of making pairwise comparisons of mesophiles to thermophiles where differences for individual proteins may be within the normal range for the group. In comparing mesophiles to thermophiles as a group, we find that thermophilic structures have fewer glycines in a particular region of the structure and higher thermal factors at room temperature. These results suggest the basis for thermostability may be related to protein motion rather than to static features of protein structure. ß 2000 Elsevier Science B.V. All rights reserved.
منابع مشابه
Structural basis for thermostability of beta-glycosidase from the thermophilic eubacterium Thermus nonproteolyticus HG102.
The three-dimensional structure of a thermostable beta-glycosidase (Gly(Tn)) from the thermophilic eubacterium Thermus nonproteolyticus HG102 was determined at a resolution of 2.4 A. The core of the structure adopts the (betaalpha)(8) barrel fold. The sequence alignments and the positions of the two Glu residues in the active center indicate that Gly(Tn) belongs to the glycosyl hydrolases of re...
متن کاملMolecular basis of the thermostability and thermophilicity of laminarinases: X-ray structure of the hyperthermostable laminarinase from Rhodothermus marinus and molecular dynamics simulations.
Glycosyl hydrolases are enzymes capable of breaking the glycosidic linkage of polysaccharides and have considerable industrial and biotechnological applications. Driven by the later applications, it is frequently desirable that glycosyl hydrolases display stability and activity under extreme environment conditions, such as high temperatures and extreme pHs. Here, we present X-ray structure of t...
متن کاملUsing neural networks expert system to predict protein thermostability
Some biological or chemical reactions need to be performed at high temperatures to decrease reaction time. However, many proteins are not very stable when heated. Research is needed that helps proteins to remain active and stable at high temperatures overcoming many limitations to their industrial applications. Recently we have shown that some structural features of proteins are related to the ...
متن کاملUsing a strategy based on the concept of convergent evolution to identify residue substitutions responsible for thermal adaptation.
Factors that are related to thermostability of proteins have been extensively studied in recent years, especially by comparing thermophiles and mesophiles. However, most of them are global characters. It is still not clear how to identify specific residues or fragments which may be more relevant to protein thermostability. Moreover, some of the differences among the thermophiles and mesophiles ...
متن کاملDifferent packing of external residues can explain differences in the thermostability of proteins from thermophilic and mesophilic organisms
MOTIVATION Understanding the basis of protein stability in thermophilic organisms raises a general question: what structural properties of proteins are responsible for the higher thermostability of proteins from thermophilic organisms compared to proteins from mesophilic organisms? RESULTS A unique database of 373 structurally well-aligned protein pairs from thermophilic and mesophilic organi...
متن کامل