I do not consider that both structures are plausible. The E coli and Salmonella homologues are 99% similar and must certainly have identical structures. In my opinion, the register of Dr Shi's structure, in the TM helices cited, is wrong. I base this opinion on our higher resolution structure, which shows clear side-chain density inconsistent with the helical register built by Dr Shi. Our structures, however, do agree in all the other helices.
Chris Miller