TABLE 1.

Spore titers of SpoIID mutants^a

Strain	SpoIID mutation	Avg spore titer	Avg sporulation (% of wild type)
KP7	spoIID298	0 × 108	0.00
PY79	Wild type	1.8 × 108	100.00
KP1124	GFP-SpoIID	2.1 × 108	116.67
KP1065	Y65A	1.8 × 108	100.00
KP1066	R66A	2.6 × 108	144.44
KP1067	E73A	2.6 × 108	144.44
KP1068	E78A	2.0 × 108	111.11
KP1069	E79A	5.5 × 108	305.56
KP1070	Y80A	8.4 × 107	46.67
KP1071	S87A	2.5 × 108	138.89
KP1072	E88A	3.5 × 104	0.02
KP1125	GFP-SpoIIDE88A	1.5 × 104	0.01
KP1073	M89A	2.6 × 108	144.44
KP1074	P90A	2.6 × 108	127.78
KP1075	K94A	1.1 × 108	61.11
KP1076	E96A	3.1 × 108	172.22
KP1077	K99A	5.0 × 108	277.78
KP1078	Q101A	1.8 × 108	100.00
KP1079	R106A	6.5M × 104	0.04
KP1142	GFP-SpoIIDR106A	1.1 × 106	0.61
KP1080	T107A	1.0 × 108	55.56
KP1081	F108A	2.2 × 108	122.22
KP1082	D128A	1.6 × 108	88.89
KP1083	D129A	1.6 × 108	88.89
KP1084	T130A	2.0 × 108	111.11
KP1085	Q134A	1.8 × 108	100.00
KP1086	Y136A	3.0 × 108	166.67
KP1087	K137A	1.5 × 108	83.33
KP1088	T164A	1.3 × 108	72.22
KP1089	T170A	1.8 × 108	100.00
KP1090	Y171A	1.2 × 108	66.67
KP1091	F181A	2.7 × 108	150.00
KP1092	S182A	1.9 × 108	105.56
KP1093	T183A	4.0 × 108	222.22
KP1095	T188A	1.0 × 107	5.56
KP1097	E192A	2.3 × 108	127.78
KP1098	Y201A	1.3 × 108	72.22
KP1099	K203A	1.0 × 104	0.01
KP1126	GFP-SpoIIDK203A	2.2 × 108	122.22
KP1100	S204A	1.6 × 108	88.89
KP1101	S207A	2.5 × 108	138.89
KP1102	D210A	2.0 × 107	11.11
KP1127	GFP-SpoIIDD210A	1.3 × 105	0.07
KP1103	S213A	2.4 × 108	133.33
KP1104	K215A	3.8 × 108	211.11
KP1105	T219A	3.3 × 108	183.33
KP1106	K220A	1.3 × 108	72.22
KP1107	T221A	3.5 × 108	194.44
KP1108	T223A	2.6 × 108	144.44
KP1109	E226A	2.6 × 108	144.44
KP1110	Q228A	3.6 × 108	200.00
KP1111	Q229A	3.7 × 108	205.56
KP1112	K230A	2.6 × 108	144.44
KP1113	K234A	1.5 × 108	83.33
KP1114	S239A	1.3 × 108	72.22
KP1115	T262A	1.2 × 108	66.67
KP1116	K282A	2.0 × 108	111.11
KP1117	R283A	2.0 × 108	111.11
KP1118	D286A	1.5 × 108	83.33
KP1119	F295A	2.3 × 108	127.78
KP1120	H297A	1.4 × 105	0.08
KP1121	V299A	1.7 × 108	94.44
KP1122	M301A	2.9 × 107	16.11
KP1123	Q303A	3.1 × 108	172.22

^aHeat kill assays were performed (31) on strains containing each spoIID mutant. Three mutations (E88A, R106A, and K203A) drastically lowered spore titers, while four other mutations lowered spore titers to intermediate levels (T188A, D210A, H297A, and M301A). For this study, we focused on those mutations causing a severe sporulation block and one mutation with an intermediate spore titer as a representative of the intermediate group. Strains further characterized in this study are indicated in boldface.