Table 1. Effect of side chain properties of the terminal amino acid on utilization of dipeptides by PA14 (WT), the dppBCDF mutant (Dpp) and the SBP penta mutant (SBP).

Dipeptide utilization		2nd amino acid (C-terminal)
		nonpolar			acidic			uncharged
		WT	Dpp	SBP	WT	Dpp	SBP	WT	Dpp	SBP
1st amino acid (N-terminal)	nonpolar	68a	46	37	13	11	11	29	16	12
	acidic	12	10	8	0	0	0	2	2	2
	uncharged	22	12	7	7	6	5	9	4	2

^a Numbers of dipeptides used by the strains as sole nitrogen source.