GENOMICS: REVOLUTIONIZING MEDICINE

GenBank — and other sequence databases
In general, genome sequencing projects are large collaborative efforts among many laboratories, so computer networks are indispensable. The networks enable access to genomic databases containing the base sequences and/or amino acid sequences that have been determined and submitted for a particular organism. One of the best known of these databases is GenBank, which began in 1983, as part of the Life Sciences Division at the Los Alamos National Laboratory in New Mexico. It is now accessed through the National Library of Medicine in Bethesda, Maryland.

Computer models of protein structures
Scientists often describe a much-sought solution to a problem as a "holy grail" — a biblical reference that is used to mean something that is of the utmost significance. The search for predictive models of protein structures has now reached that exalted status. To date, researchers have identified a four-level hierarchy of protein structures — beginning with the primary structures that link amino acids together in the protein chain — and are cataloging what is in effect a continuum of protein structures. These models of the protein landscape in which pathogens function are of enormous importance — because the structures are so integral to function.

Upper left: Oxy-hemoglobin, showing secondary protein structure. The spiral form that is visible here is an alpha-helix.

Upper right: Surface glycoprotein of a T-cell, showing secondary protein structure. The flat sheets shown here are known as beta-sheets.

Lower left: GCN4, a gene-regulatory protein, showing tertiary protein structure. This intriguing structure is known as a leucine zipper, because its double strands unzip in much the same way as DNA.

Lower right: 1RMD, a DNA-binding protein, showing tertiary structure. This structure is known as a RING finger.