Extended Data Table 4.

Diffusion coefficients

Protein conformation	[NaCI] (mM)	Mean ± S.D. (10−3 µm2s−1)
EcMutS sliding clamp	100	43 ± 16
EcMutS-EcMutL complex	50	4±2
	75	4±3
	100	4±2
	125	5±3
	150	5±3
Fast diffusing EcMutL	25	453 ± 311
	100	888 ± 393
	150	1716 ±623
	200	2220 ± 778
EcMutS-EcMutL(R95F) complex	100	3±2
(EcMutS)-EcMutL-EcMutH*	100	10±10†
EcMutS-EcMutL-EcMutH‡	50	4±2
	75	5±3
	100	5±3
Free EcMutL-EcMutH complex§	50	24 ±23
	100	41 ± 34∥
	150	118 ±151

^*Oscillating complexes potentially containing unlabelled EcMutS (EcMutS) with co-localized EcMutL-Cy3 and EcMutH-AF647.

^†A two-sample t-test suggests a significant difference (P=0.001) in diffusion coefficient between the EcMutS-EcMutL complex and (EcMutS)-EcMutL-EcMutH at 100 mM NaCl.

^‡Complexes containing co-localized EcMutS-AF555, unlabelled EcMutL and EcMutH-AF647.

^§See Methods.

^∥A two-sample t-test suggests a significant difference (P<0.0001) in diffusion coefficient between the free EcMutL-EcMutH complex and (EcMutS)-EcMutL-EcMutH at 100 mM NaCl.