Multitask ATPases (NBDs) of bacterial ABC importers type I and their interspecies exchangeability

We would like to thank Herminia de Lencastre (ITQB-AX NOVA), Adriano Henriques (ITQB-AX NOVA) and PaulaTamagnini (i3S) for the gift of chromosomal DNA, Paulo Tavares (I2BC-CNRS) and Adriano Henriques for the gift of flagellin and anti-sigmaA antibodies, respectively, and Diogo Pereira for carrying out some growth kinetic assays. This work was supported by the FundacAo para a Ciencia e a Tecnologia [Grant Numbers PTDC/BIA-MIC/30696/2017 to ISN and UID/Multi/04378/2019 to Unidade de Ciencias Biomoleculares Aplicadas UCIBIO; and fellowship PD/BD/105737/2014 to F.L.].ATP-binding cassette (ABC) type I importers are widespread in bacteria and play a crucial role in its survival and pathogenesis. They share the same modular architecture comprising two intracellular nucleotide-binding domains (NBDs), two transmembrane domains (TMDs) and a substrate-binding protein. The NBDs bind and hydrolyze ATP, thereby generating conformational changes that are coupled to the TMDs and lead to substrate translocation. A group of multitask NBDs that are able to serve as the cellular motor for multiple sugar importers was recently discovered. To understand why some ABC importers share energy-coupling components, we used the MsmX ATPase from Bacillus subtilis as a model for biological and structural studies. Here we report the first examples of functional hybrid interspecies ABC type I importers in which the NBDs could be exchanged. Furthermore, the first crystal structure of an assigned multitask NBD provides a framework to understand the molecular basis of the broader specificity of interaction with the TMDs.publishersversionpublishe