TABLE 6.

Comparison of the ion pair contents of P. furiosus and Clostridium symbiosum GDHs^a

Characteristic	Value for:
	C. symbiosum	P. furiosus
No. of IPsb per subunit	26	45
No. of IPs per residue	0.06	0.11
% of charged residues forming IPs	40	54
% of IPs formed by Arg/Lys/His	46/31/23	64/27/9
% of IPs formed by Asp/Glu	46/54	47/53
% of all Arg forming IPs	55	90
No. of residues forming 2 IPs	6	17
No. of residues forming 3 IPs	1	5
No. of 2/3/4-residue networksc	72/24/12	54/24/12
No. of 5/6/18-residue networkc	0/0/0	12/6/3
% of IPs in networks of >3 residuesc	23	62
No. of intersubunit IPsc	30	54
No. of interdomain IPs	1	7

^aAdapted from reference 368 with permission of the publisher. 

^bIP, ion pair. 

^cNumbers refer to the hexamers.