Quiz 4: Proteins As Products


Public databases contain varied information on proteins, such as the amino acid sequences of proteins, protein structure, functions, properties, applications, and protein-protein interactions. The information in protein databases is used in proteomics research, which deals with the study of structure and functions of complete set of proteins present in an organism. The databases on protein structure help in predicting the modeling proteins with unknown structures, to understand enzyme structures and in drug target modeling. The information on primary and domain structures of proteins and used for sequencing the alignments. This helps in finding homology and conserved sequences among organisms, which can be used in molecular basis of classifications. The protein structure databases offer information on experimentally determined structures of proteins, which can help in predicting structure of unknown proteins. They predict the functions of proteins based on their structures, and drug designing based on structure. Protein sequence databases also provide insights into genomic studies, such as gene expression and nucleic acid (RNA and DNA) sequences. Thus, information from these databases can also be used in protein biotechnology, for example in production of recombinant proteins and prions.

Directed molecular evolution method is used to induce changes in genomes to generate novel genome sequences, which can produce novel and valuable proteins. The gene sequence changes induced by directed molecular evolution are different from mutations that cause natural selection. Unlike natural mutations, the human induced process of directed molecular evolution concentrates on final protein product and not on the microorganism. Thus, it helps in achieving genome changes that can never occur in natural conditions.

The Protein Structure Initiative (PSI) was launched in 2000 by US National Institutes of Health, as a large scale project to identify the structures of all proteins present in humans. This research would provide information on protein structures that would help researchers to understand the functions of proteins because functions of a protein are based on its structure. The structure and configuration of a protein is the secondary and tertiary protein folding. It depends on the primary structure or amino acid sequence. This in turn depends on the nucleotide sequence of the gene that expresses the protein. The information gathered from PSI would provide advanced information on the relation between the gene sequences and protein structure. This is the basis of proteomics research. In addition, the project uses techniques, such as X-ray crystallography to construct three-dimensional structures of proteins from their amino acid sequences. The structures of unknown proteins can be modeled, on the basis of homology and comparison with structures stored in the PSI database. Thus, the initiative is also useful in understanding the role of discrepancies in protein expression in diseases.