Table 1.

Comparison of stop codon context compositional biases in ORFs and uORFS

	3' context	ORF observed Frequency	All uORFs Observed Frequency	Log Odd Ratio (uORF/ORF)
Over-represented 6-mers downstream of stop codons	ATCNNC	0.007478	0.003891	-0.942
	ATCNNT	0.009572	0.003891	-1.299
	AGGNNA	0.009423	0.004669	-1.013
	TCANNT	0.008376	0.007004	-0.258
	GCCNNC	0.003290	0.001556	-1.080
	ATANNA	0.014508	0.011673	-0.314
	GCTNNC	0.002393	0.000778	-1.621
	TAGNNT	0.006132	0.006226	0.022
	ATCNAN	0.016303	0.000778	-4.389
	ACANAN	0.011666	0.010117	-0.206
	AGGNAN	0.008376	0.006226	-0.428
	GCCNAN	0.003889	0.001556	-1.321
	TGANAN	0.010171	0.007004	-0.538
	ATANAN	0.018546	0.010895	-0.767
Under-represented 6-mers downstream of stop codons	CAANNA	0.003440	0.010117	1.556
	TTTNNT	0.014059	0.017899	0.348
	AAGNNG	0.002842	0.004669	0.716
	CAANNC	0.001645	0.000778	-1.080
	CAANNT	0.003590	0.004669	0.379
	CTCNNT	0.001346	0.003891	1.531
	CATNNT	0.003440	0.000778	-2.144
	CAANAN	0.003590	0.010895	1.601
	TTTNTN	0.013760	0.020233	0.556
	CCGNTN	0.000150	0.000778	2.379
	CTCNAN	0.001346	0.001556	0.209
	GATNAN	0.002991	0.007782	1.379
	CAANTN	0.003290	0.003113	-0.080
	CAANGN	0.002393	0.003891	0.701

The under-represented 6-mers favoured by uORFs are highlighted in bold text.