RNRdb, a curated database of the universal enzyme family ribonucleotide reductase, reveals a high level of misannotation in sequences deposited to Genbank

Table 2 Distribution of RNR proteins

Class	Subunit^a	Archaea	Archaeal viruses	Bacteria	Bacteriophages	Eukaryotes	Eukaryotic viruses	Totals
Ia	NrdA	8	2	893	39	188	124	1254
	NrdB	8	2	910	47	247	140	1354
Ib	NrdE			605	7			612
	NrdF			647	8			655
	NrdH			393	7			400
	NrdI			633	5			638
II	NrdJ	62	4	702	18	7	1	794
III	NrdD	49		950	30	8		1037
	NrdG	48		923	21			992
All classes	NrdR	6		1268				1274
Totals		181	8	7924	182	450	265	9010

Distribution of RNR classes and NrdR regulator among cellular domains and viruses.
^a Protein roles for subunits are catalytic component (NrdA, NrdE), radical harbouring component (NrdB, NrdF), reductant (NrdH), flavodoxin component (NrdI), core enzyme (NrdJ, NrdD), activase (NrdG), and transcriptional regulator (NrdR).

ISSN: 1471-2164