Illustration of NA, NA, NA, NC and NC

Copyright information:Taken from "Identification of hot spot residues at protein-protein interface"Bioinformation 2006;1(4):121-126.Published online 4 Apr 2006PMCID:PMC1891667. The interaction of K15 (PDB ID: BPTI, Chain I) to S190, S195 and V213 (trypsin, Chain E) is shown (PDB ID: 2PTC). K15 has three interacting side-chain atoms (CB, CD and NZ) and therefore the NA value is 3. Therein, the three atoms are all involved in favorable contacts (green line) and only CB participates in unfavorable contacts (red line). Thus, the NA value is 3 and NA is 1. In addition, K15 has three favorable contacts and one unfavorable contact; hence NC is 3 and NC is 1. Carbon atom: white; oxygen atom: red; Nitrogen atom: blue.