This is an integral membrane sensory domain related to the Putative vitamin uptake transporter Vut_1 (Pfam:PF02592, found in YhhQ protein from E. coli). This domain, named Vitamin uptake-like sensor (VUPS), is found in a variety of bacteria in combination with PAS (PF13188), GGDEF (Pfam:PF00990), and EAL (Pfam:PF00563) domains, and with histidine sensor kinases [1].

1: Comparative Genomics of Cyclic di-GMP Metabolism and Chemosensory Pathways in Shewanella algae Strains: Novel Bacterial Sensory Domains and Functional Insights into Lifestyle Regulation. Martin-Rodriguez AJ, Higdon SM, Thorell K, Tellgren-Roth C, Sjoling A, Galperin MY, Krell T, Romling U; mSystems. 2022; [Epub ahead of print] PMID:35311563