Comparative analysis of specificity in protein-protein interactions. Part III.: Models of the gene expression based on the sequential complementary coding of some pituitary proteins.

Using a computerized step-by-step comparative method to analyze the amino acid regularities of some pituitary peptide hormones we found several peptide sequences by intra- and intermolecular P-P positions in which most of the amino acids were complementarily coded. Some of these specifically coded sequences may be responsible for the intramolecular specific interactions and so for the secondary and tertiary structures. However the others may be the molecular basis of specific intermolecular interactions. Such a specific coding machinery may have some consequences regarding the structure and organisation of the genome and the transcription mechanism: 1. the pituitary proteins may be the results of circular transcriptions; 2. palindrome sequences may have a role in coding the specifically interacting protein parts. As a possible mechanism for understanding the transcription of mRNAs for interacting proteins, functioning on the basis of complementary coding of some protein parts, a new "honeycomb" DNA structure is presented. Since the informational and transcriptional complementarity of some proteins has a consequence, namely the possible chemical complementarity of mentioned amino acids, some possible models of non-covalent amino acid interactions have been presented.