abf1 and rap1 are general regulatory factors grfs that contribute to transcriptional activation of a large number of genes as well as to replication silencing and telomere structure in yeast in spite of their widespread roles in transcription the scope of their functional targets genome wide has not been previously determined here we use microarrays to examine the contribution of these essential grfs to transcription genome wide by using ts mutants that dissociate from their binding sites at 37 degrees c we then combine this data with published chip chip studies and motif analysis to identify probable direct targets for abf1 and rap1 we also identify a substantial number of genes likely to bind rap1 or abf1 but not affected by loss of grf binding interestingly the results strongly suggest that rap1 can contribute to gene activation from farther upstream than can abf1 also consistent with previous work more genes that bind abf1 are unaffected by loss of binding than those that bind rap1 finally we show for several such genes that the abf1 c terminal region which contains the putative activation domain is not needed to confer this peculiar memory effect that allows continued transcription after loss of abf1 binding.