Table 2.

Putative hydrogen bonds between flavin ring and PHBH for in and out flavin conformers

Flavin atom	In conformer	Distance, Å	Out conformer	Distance, Å
N1:	Gly-298 NH	3.10	HOH 430	3.17
			HOH 503	3.30
	Leu-299 NH	2.95	HOH 430	2.82
C2⩵O	Asn-300 NH	3.12	HOH 428	3.04
	Asn-300 Nδ	3.15
N3—H	Val-47 O	2.91	DOB* 396 O	2.75
C4⩵O	Gly-46 NH	3.10	Trp-222 OH	3.00
	Val-47 NH	3.13	HOH 492	3.01
N5:	—	—	HOH 426	2.94

^*2,4-di-OHB.