Analysis of inverted repeats in primary structure of proteins.

A computer program has been developed to locate exact inverted repeating subsequences present anywhere in the given primary structure of proteins or nucleic acids. The output is amenable to protein sequence/nucleic acid query (PSQ/NAQ) packages. Our analysis has shown that there is a large number of proteins which have inverted repeats of more than four amino acid residues in length. However, the number is small when conditions such as the existence of more than 20 inverted repeats in given sequence or the existence of inverted repeats having more than five different types of amino acids are applied.