The tryptophan pathway genes of the Sargasso Sea metagenome: new operon structures and the prevalence of non-operon organization

Table 6 Frequency of scaffolds and contigs containing unusual organizations of trp genes.

Gene order (enclosed)*	No of occurences†	Gene order (partial) ‡	No of occurences
X→E→X	16	E→X	55
X→G→X	42	X→G	88
X→D→X	3	G→X	108
X→C→X	5	X→D	16
X→F→X	2	D→X	8
X→B→X	7	X→C	16
X→A→X	5	F→X	6
X→B→A(→X)	9	X→B	69
(X→) E→G→X	44	B→X	49
		X→A	16
Total	133	Total	431

* Gene order (enclosed), organizations of one and two trp operons enclosed between non-trp genes; † Number of occurrences, number of contigs and scaffolds carrying the organization; ‡ Gene order (partial), pairs of trp and non-trp genes that are inconsistent with classical organization.

ISSN: 1474-760X