Fig. 10

DissectHMMER analysis of Q9K8K1_BACHD. The sugar transporter group contains 4 independent domain hits to the sequence Q9K8K1_BACHD : MFS_1 (a 12-TM lactose/H+ symporter with a total FPR of 0.0), MFS_2 (a 12-TM glucose/H+ symporter with a total FPR of 0.18), Sugar_tr (a 12-TM d-xylose/d-glucose transporter with a total FPR of 0.54) and EIIC-GAT (10-TM L-gulonate sugar-specific transporter with a total FPR of 0.94). This fold-related cohort of sugar transporter domains spans a total FPR of between 0.00 and 0.94 and a structurally-derived %Id range of between 6.5 and 100 (good RMSD between 0 and 4.79). The next group is a cohort of proton transporters made up of the Na_H_Exchanger (a 12-TM sodium/H+ antiporter) and COX1 (a 12-TM dual proton pumps) domains. This group spans between a total FPR of between 0.18 and 0.76 with an unimpressive structurally-derived %Id of between 1.7 and 6.7 (bad RMSD range of between 4.99 and 7.4). Furthermore, the Na_H_Exchanger domain is an antiporter that is structurally different from the sugar symporters. And for the last group of peptide/amino-acid transporter, which is made up of the OPT and BCCT domain, it spans a total FPR of between 0.98 and 1.01 with a low %Id of 3.1. Taken together, Q9K8K1_BACHD is neither a proton transporter nor a peptide/amino-acid transporter given the low sequence identity and structural similarity. Rather, Q9K8K1_BACHD is a sugar transporter and particularly, a lactose/H+ symporter