RpoD promoters in Campylobacter jejuni exhibit a strong periodic signal instead of a -35 box.
Petersen L, Larsen TS, Ussery DW, On SL, Krogh A. RpoD promoters in Campylobacter jejuni exhibit a strong periodic signal instead of a -35 box. J Mol Biol. 2003 Mar 07; 326(5):1361-72.