primary structure of a peptide or polypeptide amino acid all amino acid residues identified herein are in the natural l configuration in keeping with standard polypeptide nomenclature j biol chem 243 3557 59 1969 abbreviations for amino acid residues are as shown in the following table of correspondence it should be noted that all amino acid residue sequences are represented herein by formulae whose left to right orientation is in the conventional direction of amino terminus to carboxy terminus furthermore it should be noted that a dash at the beginning or end of an amino acid residue sequence indicates a bond to a radical such as h and oh hydrogen and hydroxyl at the amino and carboxy termini respectively or a further sequence of one or more amino acid residues up to a total of about fifty residues in the polypeptide chain base pair bp a partnership of adenine a with thymine t or of cytosine c with guanine g in a doable stranded dna molecule constitutive promoter a promoter where the rate of rna polymerase binding and initiation is approximately constant and relatively independent of external stimuli examples of constitutive promoters include the cauliflower mosaic virus 35s and 19s promoters described by poszkowski et al embo j 3 2719 1989 and odell et al nature 313 810 1985 enzyme a protein polypeptide peptide rna molecule or multimeric protein capable of accelerating or producing by catalytic action some change in a substrate for which it is often specific expression vector a dna sequence that forms control elements that regulate expression of structural genes when operatively linked to those genes expression.