Table 1.
Representative viruses with different T number classes having coat proteins with the HK97 fold.
| Capsid | T- number |
Maximum diameter (nm) |
Family | Unique properties | References |
|---|---|---|---|---|---|
|
T. maritima
encapsulin |
1 | 24 | – | 60° rotation of E-loop | (Sutter et al., 2008) |
| SsP2 | 3 | 32 | – | Crenarchaeota provirus | (Heinemann et al., 2011) |
|
M. xanthus
encapsulin |
3 | 32 | – | (McHugh et al., 2014) | |
| PfV encapsulin | 3 | 36 | – | Euryarchaeota | (Akita et al., 2007) |
| 029 | 3 Q=5 |
45 wide 54 long |
P | C-terminal addition of Big2 domain | (Morais et al., 2005) |
| C1 | 4 | 50 | P | Insertion domain and additional density across twofold axes |
(Aksyuk et al., 2012) |
| P2 | 7d | 60 | M | Also makes T=4 capsids (40 nm diameter) with P4 Sid | (Dearborn et al., 2012) |
| Sf6 | 7/ | 60 | P | I-domain | (Parent et al., 2012b) |
| A | 7/ | 60 | S | (Lander et al., 2008) | |
| T7 | 7* | 60 | P | Frameshift produces C-terminal extension in ~ 10% of proteins |
(Agirrezabala et al., 2007; Guo et al., 2014; lonel et al., 2011) |
| Syn5 | 7* | 60 | P | Small I-domain | (Gipson et al., 2014; Pope et al., 2007) |
| SPP1 | 7/ | 61 | S | Extended P-domain | (White et al., 2012) |
| HSTV-1 | 7/ | 62 | P | Infects Archaea | (Pietila et al., 2013) |
| K1E/K1-5 | 7* | 63 | P | C-terminal extension | (Leiman et al., 2007) |
| Gifsy-2 | 7/ | 63 | – | Prophage | (Effantin et al., 2010) |
| 80a | 7/ | 63 | S | P-loop in P-domain involved in threefold interactions |
(Spilman et al., 2011) |
| P-SSP7 | 7* | 65 | P | Long F-loop makes contact across twofold axes, extended N-arm |
(Liu et al., 2010) |
| TP901-1 | 7* | 66 | S | (Bebeacua et al., 2013) | |
| HK97 | 7/ | 66 | S | Covalent crosslinks in mature capsid |
(Gertsman et al., 2009; Helgstrand et al., 2003; Wikoff et al., 2000) |
| BPP-1 | 7/ | 67 | P | Altered topology, extended N-arm | (Zhang et al., 2013) |
| CUS-3 | 7/ | 69 | P | I-domain | (Parent et al., 2014) |
| £15 | 7/ | 70 | P | Altered topology | (Baker et al., 2013; Jiang et al., 2008) |
| CW02 | 7/ | 70 | P | (Shen et al., 2012) | |
| P22 | 7/ | 71 | P | I-domain | (Chen et al., 2011; Parent et al., 2010a) |
| Basilisk | 9 | 72 | S | (Grose et al., 2014) | |
| SIO-2 | 12 | 80 | S | (Lander et al., 2012) | |
| T5 | 13l | 90 | S | (Effantin et al., 2006) | |
| T4 | 13/ Q = 20 |
90 wide 200 long |
M | Insertion in E-loop and separate protein for penton position |
(Fokine et al., 2005b) |
| Bellamy | 13 Q = 24 |
95 wide 135 long |
M | Personal communication Roger Hendrix |
|
| SPO1 | 16 | 108 | M | (Duda et al., 2006) | |
| HSV-1 | 16 | 125 | H | Additional middle and upper domains |
(Baker et al., 2005; Zhou et al., 2000) |
| PRV | 16 | 125 | H | Additional middle and upper domains |
(Homa et al., 2013) |
| RRV | 16 | 130 | H | Additional middle and upper domains |
(Zhou et al., 2014) |
| MCMV | 16 | 131 | H | Additional middle and upper domains |
(Hui et al., 2013) |
| ϕM12 | 191 | 100 | M | (Stroupe et al., 2014) | |
| N3 | 19* | 119 | M | Personal communication Roger Hendrix |
|
| PAU | 25 | 130 | M | Personal communication Roger Hendrix |
|
| ϕRSL1 | 27 | 123 | M | (Effantin et al., 2013) | |
| PBS1 | 27 | 140 | M | Personal communication Roger Hendrix |
|
| ϕKZ | 27 | 145 | M | (Fokine et al., 2005a) | |
| 121Q | 28* | 140 | M | Personal communication Roger Hendrix |
|
| Phage G | 52* | 185 | M | Personal communication Roger Hendrix |
P – Podovirdae; M – Myovirdae; S – Siphovirdae; H – Herspesvirdae; ‘-‘ Unclassified family
*
Skew class, but handedness was not determined
l – laevo
d – dextro