Cell Structure Changes in the Hyperthermophilic Crenarchaeon Sulfolobus islandicus Lacking the S-Layer

Abstract

The S-layer is considered to be the sole component of the cell wall in Sulfolobales , a taxonomic group within the Crenarchaeota whose cellular features have been suggested to have a close relationship to the last archaea-eukaryote common ancestor. In this study, we genetically dissect how the two previously characterized S-layer genes as well as a newly identified S-layer-associated protein-encoding gene contribute to the S-layer architecture in Sulfolobus . We provide genetic evidence for the first time showing that the slaA gene is a key cell morphology determinant and may play a role in Sulfolobus cell division or/and cell fusion.