The ywcE gene codes for a holin-like protein that localizes to the cell and spore membranes [1]. It is expressed at the onset of sporulation and transcription is repressed during growth by the transition-state regulator AbrB. YwcE is an 83-residue protein with three trans-membrane regions and a highly charged C-terminal tail. Moreover, YwcE has a dual start motif, which plays a role in the regulation of class I or class II holins. It is likely to have the N terminus on the outside of the membrane and the C terminus in the cytoplasm [2]. This family is found in YwcE proteins in Bacilli.

1: Sporulation during growth in a gut isolate of Bacillus subtilis. Serra CR, Earl AM, Barbosa TM, Kolter R, Henriques AO; J Bacteriol. 2014;196:4184-4196. PMID:25225273

2: A gene encoding a holin-like protein involved in spore morphogenesis and spore germination in Bacillus subtilis. Real G, Pinto SM, Schyns G, Costa T, Henriques AO, Moran CP Jr; J Bacteriol. 2005;187:6443-6453. PMID:16159778