Construction and characterization of chimeric proteins composed of type-1 and type-2 periplasmic binding proteins MglB and ArgT

• Published in: Bioscience, biotechnology, and biochemistry Vol. 68; no. 4; pp. 808 - 813
• Main Authors: Kashiwagi, K. (Japanese Foundation for Cancer Research, Tokyo (Japan)), Fukami Kobayashi, K, Shiba, K, Nishikawa, K
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01-04-2004; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: BINDING PROTEINS; Biological and medical sciences; CHIMAERAS; chimeric protein; Circular Dichroism; Electrophoresis; evolution of protein folding; Fundamental and applied biological sciences. Psychology; GENES; periplasmic binding protein; Periplasmic Binding Proteins - chemistry; Periplasmic Binding Proteins - genetics; Periplasmic Binding Proteins - metabolism; Protein Denaturation; Protein Folding; Protein Structure, Secondary; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism; Solubility; Temperature; Characterization; periplasmic binding protein; Binding protein; evolution of protein folding; chimeric protein
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.68.808

The respective type-1 and type-2 periplasmic binding proteins (PBPs) MglB and ArgT are believed to have evolved from a common ancestor into siblings showing topological differences in their main chain connectivity. At first glance, they show similar structure. But, more detailed examination reveals that the chain connectivity of ArgT is more convoluted than that of MglB. Reflecting that complexity, the folding of ArgT is complicated and involves intermediate folds. On the other hand, the folding of MglB is a simple two-state transition. In the present study, we constructed and characterized several chimeras made up of various subdomains of MglB and ArgT with the aim of gaining insight into the evolution of protein folding and protein structure. Although these chimeras did not fold as compactly as their parental proteins, some did exhibit cooperative folding, which suggests that novel proteins with new connectivity and new folding pathways could have emerged at a fairly high rate throughout the evolution of proteins.