Fig. 2. Comparison of deduced amino acid sequences of NO synthase from land crab, insects, mollusk and human. Land crab (Gecarcinus lateralis) NOS was aligned with NOS sequences from insects (Manduca sexta, Bombyx mori, Rodnius prolixus, Anopheles stephensi and Drosophila melanogaster), mollusk (Aplysia californica) and human (iNOS, nNOS, eNOS) using the ClustalW program (see Materials and methods). Identities in all 10 sequences are highlighted in black. Boxes with broken borders identify highly conserved binding sequences for heme, tetrahydrobiopterin (H4), calmodulin, FMN, FAD and NADPH. Inverted triangles indicate amino acid sequence deviation in the FAD binding motif of Gl-NOS. Regular triangles indicate the two conserved cysteine residues in the zinc tetrathiolate cluster. Accession numbers: Rhodnius prolixus, Q26240; Anopheles stephensi, O61608; Bombyx mori, BAB85836; Drosophila melanogaster, Q27571; Manduca sexta, T30555; Aplysia californica, AF288780; and human iNOS (AAB49041), eNOS (NP000594) and nNOS (NP000611).