Table IV. Conserved GTPase domains and EF-hand motifs of Gem1p are required for function.

gem1Δ strain containing pRS416 plus:	Percent tubular network	Percent collapsed	Percent mutant
No insert	0.9 ± 1.3	15.8 ± 3.4	83.3 ± 4.3
GEM1	59.9 ± 6.2	25.4 ± 5.7	14.6 ± 7.1
GTPase I domain mutations:
gem1 (K18A)	3.1 ± 1.3	21.1 ± 3.5	75.8 ± 3.2
gem1 (S19N)	2.3 ± 0.9	18.6 ± 7.8	79.1 ± 7.4
gem1 (T33A)	57.8 ± 6.1	28.5 ± 4.7	13.7 ± 5.4
GTPase II domain mutations:
gem1 (K461A)	13.1 ± 6.8	31.6 ± 13.8	55.3 ± 12.0
gem1 (S462N)	3.2 ± 2.6	16.7 ± 1.6	80.1 ± 2.4
gem1 (T480A)	13.9 ± 11.7	37.9 ± 10.3	48.3 ± 5.9
EF-hand motif mutations:
gem1 (E225K)	28.7 ± 2.9	33.8 ± 2.4	37.5 ± 2.2
gem1 (E354K)	42.2 ± 3.5	30.7 ± 7.6	27.0 ± 10.4
gem1 (E225K, E354K)	14.3 ± 6.7	30.3 ± 4.9	55.3 ± 7.0

n _cells > 300.

Mitochondria were visualized by expressing mito-GFP.

Percent tubular network contains wild-type morphology shown in Fig. 3 A.

Percent collapsed contains aberrant morphology shown in Fig. 3 B.

Percent mutant category contains aberrant morphologies shown in Fig. 3 (C–E).