Table 1.

Properties of representative V_H1–69 antiviral antibodies.

Virus	Antibody	VH1–69 allele	Genetic features	CDRH3 length1	Epitope	Recognition properties	Neutralization breadth	PDB	Reference
Influenza	CR6261	F	Hydrophobic Ile-Phe (IF) sequence at the tip of CDRH2 [Met-Phe (MF) for F10] with a conserved Tyr (Y) in CDRH3 to give an IFY motif	12	HA stem	Heavy chain only binding; CDRH2 dominant	Influenza A group 1	3GBM	[27]
	F10	F		15				3FKU	[11]
	CR9114	F		12		Heavy chain dominant; CDRH2 dominant	Influenza A group 1 and 2 viruses	4FQI	[28]
	27F3	F		14				5WKO	[29••]
	2G1	F	Hydrophobic IF (FF for F045–092) at the tip of CDRH2	11	HA head RBS	Heavy chain dominant; CDRH2 and H3 mediated	Influenza A group 1	4HG4	[32]
	8M2	F		14				4HFU	[32]
	F045–092	F		23		Heavy chain only binding; CDRH3 dominant	Influenza A (group 1 and 2)	4O58; 4O5I	[30,70]
HCV	AR3A	F	Hydrophobic I/V-P-X-F motif at the tip of CDRH2 for AR3- and HC84-class antibodies; T/S-P-I-F/S motif for HEPC3/74-class antibodies	18	E2 AR3	Heavy chain only binding; CDRH2 and CDRH3 mediated	Broadly neutralizing	6BKB	[15,60••]
	AR3B	F		19				6BKC	[15,60••]
	AR3C	F		18				4MWF	[15,44,60••]
	AR3D	F		22				6BKD	[15,60••]
	HEPC3	F		17				6MEI; 6MEJ; 6MEK	[47••]
	HEPC74	F		18				6MEH	[47••]
	HC84–1	F		10	E2 domain D	Heavy chain dominant; CDRH2 dominant	Broadly neutralizing	4JZN	[45]
	HC84–27	F		10				4JZO	[45]
	HC84–26	F		10				5ERW	[46]
HIV-1	4E10	L	Hydrophobic LL at the tip of CDRH2	18	gp41 MPER and membrane lipid	Heavy chain dominant; CDRH2 dominant	Broadly neutralizing	2FX7, 4XCF	[51,53,75,75]
	HK20	F	Hydrophobic IF at the tip of CDRH2	13	gp41 HR1	Heavy chain dominant; CDRH2 dominant	Less breadth and potency	2XRA	[56]
	D5	F		10				2CMR	[55]
	17b	L	Hydrophobic IL at the tip of CDRH2	19	gp120 coreceptor-binding site	Heavy chain dominant; CDRH2 and H3 mediated	Limited neutralizing	1RZ8 1GC1, 1G9N, 1G9M	[20,77,78]
	VRC13	F	Polar ST at the tip of CDRH2	21	gp120 CD4bs	CDRH3 dominant	Broadly neutralizing	4YDJ	[19]

¹Based on Kabat numbering, in which the CDRH3 length is 2 amino acids shorter than in the IMGT definition.