Table S1.

Meridional reflections

Reflection	WT				HM
	SL = 2.0 μm spacing, nm	SL = 2.4 μm spacing, nm	ΔSpacing, %	Intensity ratio	SL = 2.0 μm spacing, nm	SL = 2.4 μm spacing, nm	ΔSpacing, %	Intensity ratio
C2,1	23.04 ± 0.03	23.04 ± 0.03	−0.01 ± 0.17	1.28 ± 0.24	23.10 ± 0.02	23.03 ± 0.04	−0.30 ± 0.20	1.13 ± 0.20
C2,2	22.21 ± 0.03	22.16 ± 0.03	−0.15 ± 0.09	1.40 ± 0.11*	22.21 ± 0.04	22.11 ± 0.04	−0.45 ± 0.38	1.37 ± 0.16
M2	21.53 ± 0.01	21.62 ± 0.09	0.28 ± 0.05*	2.46 ± 0.28*	21.42 ± 0.02	21.45 ± 0.04	0.14 ± 0.15	1.34 ± 0.20
Tn2	19.06 ± 0.04	19.05 ± 0.03	−0.05 ± 0.25	0.89 ± 0.12	19.09 ± 0.06	19.12 ± 0.04	0.22 ± 0.37	1.18 ± 0.20
M3	14.30 ± 0.001	14.30 ± 0.001	0.00 ± 0.002	1.14 ± 0.05	14.3 ± 0.01	14.33 ± 0.01	0.21 ± 0.05	1.05 ± 0.14
Tn3	12.84 ± 0.02	12.95 ± 0.02	0.86 ± 0.21*	2.05 ± 0.02*	12.77 ± 0.03	12.82 ± 0.03	0.39 ± 0.31	1.33 ± 0.16
C4	10.94 ± 0.01	10.94 ± 0.01	0.00 ± 0.002	1.12 ± 0.14	11.04 ± 0.02	11.00 ± 0.01	−0.36 ± 0.14	1.23 ± 0.13
M4	10.65 ± 0.01	10.65 ± 0.01	0.00 ± 0.002	1.40 ± 0.23	10.63 ± 0.01	10.63 ± 0.01	0.00 ± 0.07	1.17 ± 0.16
M5	8.56 ± 0.003	8.56 ± 0.002	0.07 ± 0.04	1.05 ± 0.14	8.54 ± 0.01	8.54 ± 0.01	0.00 ± 0.04	1.13 ± 0.18
M6	7.17 ± 0.002	7.18 ± 0.002	0.14 ± 0.03*	1.42 ± 0.12*	7.22 ± 0.004	7.22 ± 0.003	−0.03 ± 0.05	1.35 ± 0.18

Meridional reflections were recorded at short (SL = 2.0 μm) and long (SL = 2.4 μm) SL. Calibrated periodicities were calculated from the position of the peak of the reflection on the meridional projection of the 2D X-ray diffraction pattern. ΔSpacing is the percentage change in periodicity in going from short to long SL, relative to the periodicity recorded at the short SL. Intensity ratio is the ratio of the reflection intensity recorded at the long SL relative to the short SL. C, myosin-binding protein C; M, myosin; Tn, troponin.

^*P < 0.05.