Table 1. Comparisons of 5S rRNA system among four representatives of excavate and with archaea and common eukaryotes.

Organism			Archaea	Excavate						Common eukaryotes
				Gl			Tv	Tc	Ng
				WB	GS	P15
5S rRNA gene	Copy number		Few [48]	8 [16]	Y* (?)	6 [21]	Many [23]	≈1600 [24]	279*	Many
	Tandem arrangement		N	N	N*	N	Y	Y	Y*	Y
	Located with rDNA Units		Y	N	N*	N	N	N	N*	N
Promoter	ICR		N	N*	N*	N*	Y [23]	Y [24]	Y*	Y
	TATA-box		Y	Y*	N*	N*	Y [23]	N*	Y*	Y
Transcription factor	TFIIIA		N	N	N*	N*	Y*	N*	N*	Y
	TFIIIB	TBP	Y [40]	Y [17]	Y*	Y*	Y*	Y*	Y*	Y
		TFB/BRF	Y [40]	Y[17]	Y*	Y*	Y*	Y*	Y*	Y
		B′′	N	N	N*	N*	Y*	Y*	Y*	Y
	TFIIIC	TFIIIC 102	N	N	N*	N*	Y*	Y*	Y*	Y
		TFIIIC 63	N	N	N*	N*	Y*	Y*	Y*	Y
RNA pol III specific subunit	C34		Y [17]	Y [17]	Y*	Y*	Y*	Y*	Y*	Y
	C82		N	Y*	Y*	Y*	Y*	N*	Y*	Y
	C31		N	N	N*	N*	N*	N*	N*	Y
	C17		N	N	N*	N*	N*	N*	Y*	Y
	C53		N	N	N*	N*	Y*	Y*	Y*	Y
L5 protein			Y [46]	Y	Y	Y	Y	Y	Y	Y

Note: Y, present; N, absent; (?), unknown copy number;

^*identified in this work.

Organism abbreviations: Gl: Giardia lamblia; Tv: Trichomonas vaginalis; Tc: Trypanosoma cruzi; Ng: Naegleria gruberi.