Dear All, I have a protein, which contains fragment aa 239-251. The protein has been fitted its map with 2 different (minor difference) resolution, and thus I have 2 PDB. For PDB 1 (the first resolution), the H-bonds inside aa 239-251 include: #2 Gly 245.A N-Asn 242.A O 2.708A #2 Asn 242.A N-Tyr 246.A O 3.120 A #2 Val 248.A N-Val 240.A O 3.120 A #2 GLN 251.A N-Ser 238.A 0 3.033 A For PDB 2 (the second resolution), the H-bonds inside aa 239-251 include: #0 Gly 245.A N-Asn 242.A O 2.715A #0 Asn 242.A N-Tyr 246.A O 3.1206 A #o Val 248.A N-Val 240.A O 2.858 A #0 GLN 251.A N-Ser 238.A 0 3.074 A Naked eye check found the H-bonds in PDB 1 were almost the same H-bonds in PDB 2. However for PDB 2, aa23-242 and aa 247-251 form 2 strands, but for PDB 1, it was a un-disconnected loop for aa 239-251. Will you please explain how chimer assign beta strand? Best regards. Smith