Table 1. Hydrogen bonds involved in the formation of the dimer contact region in HUSpm (according to PISA and WHATIF).

	A.a 1 position	A.a 1 name	Atom 1	Distance, Å	A.a 2 name	A.a 2 position	Atom 2
1	−1	GLY	O	2.9	GLU	43	N
2	1	MET	N	2.8	GLU	43	O
3	1	MET	O	2.8	SER	45	N
4	3	LYS	N	3.0	SER	45	O
5	35	LYS	NZ	2.7	GLY	48	O
6	43	GLU	N	2.9	GLY	−1	O
7	43	GLU	O	2.8	MET	1	N
8	45	SER	N	2.9	MET	1	O
9	45	SER	O	3.0	LYS	3	N
10	48	GLY	O	2.7	LYS	35	NZ
11	77	LYS	N	2.8	ASN	92	OD1
12	77	LYS	O	2.8	ASN	92	ND2
13	92	ASN	OD1	2.8	LYS	77	N
14	92	ASN	ND2	2.8	LYS	77	O

Hydrogen bonds with donor-to-acceptor distances shorter than 3.5 Å are listed. Hydrogen bonds unique for HUSpm are given in bold.