Patent ID: 8354246

Claim:
A method of inhibiting a Gram-negative bacterial RNA polymerase comprising: (a) providing a lariat peptide of formula (I): wherein: (i) X is an amino acid residue containing a backbone nitrogen atom; (ii) Y is an amino acid residue containing a side-chain carboxyl group; (iii) α is a peptide segment of from about 5 to about 8 amino acid residues; (iv) β is a peptide segment of from about 6 to about 15 amino acid residues; (v) there is an amide bond between the backbone nitrogen atom of X and the side-chain carboxyl of Y; and (vi) wherein the lariat peptide has less than 25% amino acid sequence identity with microcin J25 (MccJ25); and b) contacting a Gram-negative bacterial RNA polymerase with the lariat peptide of formula (I), thereby inhibiting RNA synthesis activity of the Gram-negative bacterial RNA polymerase, wherein the lariat peptide of formula (I) is selected from the group consisting of RES-701-1, RES-701-2, RES-701-3 and RES-701-4.