Superoxide dismutases (SODs) are critical enzymes protecting cells against toxic superoxide radicals. To date, 3 types of SODs have been identified: Cu-ZnSODs, Fe-MnSODs, and NiSODs. In this study, a genome-wide analysis was performed in Sorghum bicolor to characterize SOD genes and proteins. | Turkish Journal of Biology Turk J Biol (2015) 39: 49-59 © TÜBİTAK doi: Research Article Genome-wide distribution of superoxide dismutase (SOD) gene families in Sorghum bicolor 1, 1 2 Ertuğrul FİLİZ *, Hüseyin TOMBULOĞLU Department of Crop and Animal Production, Çilimli Vocational School, Düzce University, Çilimli, Düzce, Turkey 2 Department of Biology, Faculty of Science and Arts, Fatih University, Büyükçekmece, İstanbul, Turkey Received: Accepted: Published Online: Printed: Abstract: Superoxide dismutases (SODs) are critical enzymes protecting cells against toxic superoxide radicals. To date, 3 types of SODs have been identified: Cu-ZnSODs, Fe-MnSODs, and NiSODs. In this study, a genome-wide analysis was performed in Sorghum bicolor to characterize SOD genes and proteins. Using several bioinformatics tools, we characterized a total of 8 SOD genes from the Sorghum genome. Gene structure, chromosomal distribution, tissue specific expression, conserved domain, and phylogenetic analyses of SOD genes were carried out. Additionally, 3-dimensional structures were determined and compared within each SbSOD protein. Chromosomal distributions revealed that the highest number of SOD genes was on chromosomes 1 and 10, with 2 members on each. Single segmental gene duplication was observed between the genes SbSOD2 and SbSOD5. Intron numbers of SbSOD genes ranged from 5 to 7. Motif analyses showed that SbSODs included 2 and 3 common motifs in Cu-ZnSOD and Fe-MnSODs, respectively. In addition, 3 functional domains were identified in SbSODs: 1) copper-zinc domain (Pfam: 00080) in Cu-ZnSOD; and 2) iron/manganese superoxide dismutases alpha-hairpin domain (Pfam: 00081) and 3) iron/manganese superoxide dismutases, C-terminal domain (Pfam: 02777) in Fe-MnSODs. Gene Ontology term enrichment analysis showed that 8 SOD genes have similar molecular functions and biological .