Table 1.

Average fractions 〈f〉 of H residues in soluble proteins and in different regions of membrane proteins

	Entire membrane proteins	TM	Loops entire	Loops OUT	Loops IN	Soluble proteins
〈f〉	0.56 (1)	0.69 (1)	0.47 (1)	0.48 (2)	0.45 (1)	0.44

Results for soluble proteins are taken from Table 2 of Miao et al. (20). The TM region (central layer) is a (−15,15 Å) slab along the z axis. The set of H residues (19) is defined in Materials and Methods. The statistical errors are (1 SD)/N^1/2, where N is 103 and 41 for the soluble and membrane proteins, respectively. The results for the membrane proteins are averages of results appearing in Table 2. The errors of the last digit are denoted by parentheses, e.g., 0.56 (1) = 0.56 ± 0.01. The error for soluble proteins is <0.006.