Table III
Introns and their protein products (IEP) encoded by staphylococcal Twort-like phagesa

Intron name
(phage)b	Intron 
length
(nucleotide)	Name of 
interrupted 
gene	Known or predicted function 
of interrupted gene	Name of 
IEP
	Length of
IEP
 (amino 
acid)	Known or 
predicted 
function 
of IEPc	Phages containing homologous intron at conserved DNA position
(name of interrupted gene; length of conserved region if different; % identity if less than 100)d 	
Lys-I1
(K)	876	32&30
 (lysK)	Lysin	I-KsaI	166	HNH 
endonuclease	G1 (60&42) 
ISP(201&203)
Sb-1(53&55)
A5W (lysK)
Staph1N (lysK)
A3R (lysK)
Fi200W (lysK)
676Z (lysK)
P4W (lysK)
MSA6 (lysK)	
Pol-I1
(K)	798	86&88 
(polA)	DNA 
polymerase	I-KsaII	170	Two zinc
fingers	G1 (33&19&37)
ISP (59&61&63)
Sb-1 (129&129b&129c)
A5W (polA)
Staph1N(polA)
A3R (polA)
Fi200W (polA)
676Z (polA)
P4W (polA)
MSA6 (polA)	
Pol-I2
(K)	1082	88&90
(polA)	DNA
 polymerase	I-KsaIII	269	HNH 
endonuclease	G1 (33&19&37) 
ISP (59&61&63)
Sb-1  (129&129b&129c)
A5W (polA)
Staph1N (polA; 798; 100)
A3R (polA)
Fi200W (polA; 1081; >99)
676Z  (polA)
P4W (polA; 1081; >99)
MSA6 (polA)	
nrd-I1
(Twort)	429	45&33 
(nrdI)	Ribonucleotide reductase regulatory subunit	-	NA	NA	—	
nrd-I2
(Twort)	1087	33&118 
(nrdE)	Ribonucleotide reductase large subunit	I-TwoI	243	HNH 
endonuclease	—	
tub-I1
(Twort)	325	106&NC (tmpA)	Tail tube	—	NA	NA	—	
tub-I2
(Twort)	282	106&NC (tmpA)	Tail tube	—	NA	NA	—	
tub-I3
(Twort)	252	106&NC 
(tmpA)	Tail tube	—	NA	NA	—	
ter-I1
(Twort)	1514	151&59 
(ter)	Large terminase	gp31	316	Unknown	—	
ter-I2
(Twort)	1312	59&36 
(ter)	Large terminase	gp119	320	Unknown	MSA6 (ter,221; 91)e	
ter-I3
(MSA6)	1337	ter	Large terminase	I-MsaI	323	Unknown	Twort (ter; 221; 91)e	
rec-I1
(MSA6)	1494	rec	Recombinase	I-MsaII	322	putative endonuclease 	812 (NC [homologue of A5W rec];1376; 92)

tmpA-I1
(676Ż)	305	tmpA	Tail tube	—	NA	NA	Fi200W (tmpA)
P4W (tmpA)
A3R (tmpA)	
tmpA-I2
(676Ż)	256	tmpA	Tail tube	—	NA	NA	Fi200W (tmpA)
P4W (tmpA)
A3R (tmpA)	

aCharacteristic of introns and IEP-encoding genes in phages K, G1, Twort, and A5W is given according to Stewart et al. (2009a), Kasparek et al., (2007) and Ulatowska et al. (in preparation). Characteristic of introns and IEP-encoding genes in other phages is based on homologies of relevant regions in DNA of these phages to known intron and IEP encoding sequences. The lengths of the MSA6 ter-I3 and rec-I1 introns, as well as 676Z˙ tmpA-I1 and tmpA-I2 introns were predicted based on homologies of predicted translation products of intron-encoding and -flanking regions to ter, rec and tmpA gene products of other staphylococcal Twort-like phages, respectively. Coordinates of these introns are as in the relevant GenBank files (see Table I).
bThe name of phage, in which a given intron was originally described, is in parentheses.
cNot applicable.
dHomologies of certain phage MSA6, 676Z˙ , P4W, Fi200, and A3R introns to introns of phage 812 are based on the comparison of DNA sequences of these phages with the fragments of 812 sequence that are deposited in GenBank (Acc. No. EF136586 and EF136582; Kasparek et al., 2007).
eHomology concerns 5' regions of Twort ter-I2 and MSA6-ter-I1 introns.