heptakis-L-histidino tetracopper mu4-sulfide hydroxide 1253.05078125 1256.1800537109375 293.638427734375 296.20001220703125 Cross-link 7. MOD:00303 H -6 O 1 S 1 Cu 4 C 42 H 43 N 21 O 8 S 1 Cu 4 none PSI-MOD pentakis-L-N1'-histidino-bis-L-N3'-histidino tetracopper sulfide hydroxide heptakis-L-histidino tetracopper mu4-sulfide hydroxide natural mu4-sulfido bis(bis-N1'-histidino copper)(N1'-histidino-N3'-histidino copper)(N3'-histidino hydroxide copper) A protein modification that effectively converts seven L-histidinine residues and a four-copper one-sulfur one-hydroxide cluster to heptakis-L-histidino tetracopper mu4-sulfide hydroxide. nitrous oxide reductase nosZ CuZ cluster H, H, H, H, H, H, H copper containing modified residue sulfur containing modified residue metal or metal cluster coordinated L-histidine residue