Table 4.

RecD inhibits RecA loading by RecB^D1080AC enzyme

Enzyme	Product*	RecA†	% product surviving exonuclease I digestion after:‡
			6 min	12 min	18 min
RecBCD	Chi	+	79, 66	69, 67	54
		−	<1, <1	<1, <1	<1
RecBC	Unw	+	53, 60	49, 60	52
		−	1.7, 2.1	1.4, 1.3	2.1
RecBD1080ACD	Unw	+	5.0, 3.2, 2.2	7.5, 3.1, 1.8	2.8
		−	<1, <1, 1.2	<1, <1, 1.3	<1
RecBD1080AC	Unw	+	44, 76, 41	46, 72, 47	58
		−	2.4, 3.6, 1.9	3.6, 2.9, 1.4	3.4

^*The major product from RecBCD wild-type or mutant enzyme reaction with linear pBR322 χ⁺F225 as described in the text. Chi is ssDNA labeled at the 5′ end and extending to the Chi site. Unw is full-length ssDNA labeled at the 5′ end. 

^† Reactions were conducted in the absence (−) or presence (+) of 20 μM RecA protein by using the indicated enzyme. Multiple values are from independent experiments in which samples were taken at the indicated times. The reaction with RecBCD mutant or wild-type enzyme was for 2 min under conditions described in Materials and Methods. Exonuclease I was added and samples were removed at 6, 12, and 18 min (experiment 1) or at 6 and 12 min (experiments 2 and 3). Experiment 1 is shown in Fig. 2. 

^‡ The percent of product present at the time listed after the addition of exonuclease I relative to the amount present at the end of the RecBCD enzyme reaction was determined by PhosphorImage analysis as described in Materials and Methods.