<i>OSW3</i> encodes a subtilisin-related protease that localizes to the spore wall.

<p>(A) Schematic of Osw3: SS = signal sequence; INHB = inhibitory pro-domain; PROT = protease catalytic domain. (B) AN120 (wild-type) and AN264 (<i>dit1Δ</i>) carrying a high copy OSW3-GFP plasmid (pRS424-OSW3-GFP) were analyzed by fluorescence microscopy at 5, 8, and 20 hours after transfer to sporulation medium. Arrow indicates fluorescence in the ascal cytoplasm of the <i>dit1Δ</i> mutant. Bar = 5 µm.