SEA-PHAGES | Terminase, small subunit in right arm

Link to this post \| posted 04 Jun, 2023 19:53
jawsWPI	The terminase small subunit is in the right-hand arm of the genome. Example is gene 57 in TaylorSipht (cluster AS1). This gene has a strong hit to PDB 6Z6E_C, with 99.79 probability, 3.8e-18, and 100 columns aligned out of 160. Alignment is to the helix-turn-helix-turn-helix structure of "Terminase small subunit; genome packaging, bacteriophage, DNA binding, VIRAL PROTEIN; 1.4A {Enterobacteria phage HK97}". Do not call two small terminases, nor assign terminase small subunit function to the early gene (example, gene 2 in TaylorSipht). Edited 19 Jul, 2023 19:49

Link to this post | posted 04 Jun, 2023 19:53

The terminase small subunit is in the right-hand arm of the genome. Example is gene 57 in TaylorSipht (cluster AS1). This gene has a strong hit to PDB 6Z6E_C, with 99.79 probability, 3.8e-18, and 100 columns aligned out of 160. Alignment is to the helix-turn-helix-turn-helix structure of "Terminase small subunit; genome packaging, bacteriophage, DNA binding, VIRAL PROTEIN; 1.4A {Enterobacteria phage HK97}".
Do not call two small terminases, nor assign terminase small subunit function to the early gene (example, gene 2 in TaylorSipht).

Edited 19 Jul, 2023 19:49

Link to this post \| posted 17 Jun, 2025 15:41
cdshaffer	for more discussion on this matter see this discussion: https://seaphages.org/forums/topic/5775/

Link to this post \| posted today, 18:11
CCSNH-NHTI	If we have a terminase that appears to be a large subunit in the left arm and one that appears to be a small subunit in the right arm, should they be labeled as the subunits or each just terminase? WileyE, stop1990 and stop35937.

Link to this post \| posted 14 minutes ago
debbie	HI all, I think that the answer is in this post above. Please read above. In general, the 2 genes of terminase do different things. It is a good time to check the literature on this. There are many articles that articulate what these genes do. Here is an article that describes a non-canonical display of the Terminase, large subunits parts. Zhao H, Christensen TE, Kamau YN, Tang L. Structures of the phage Sf6 large terminase provide new insights into DNA translocation and cleavage. Proceedings of the National Academy of Sciences of the United States of America. 2013;110(20):8075-8080. doi:10.1073/pnas.1301133110. The small terminase is more elusive, and sometimes we cannot find it. It can also be part of the large terminase gene. debbie

Link to this post | posted 14 minutes ago

debbie

HI all,
I think that the answer is in this post above. Please read above.

In general, the 2 genes of terminase do different things. It is a good time to check the literature on this. There are many articles that articulate what these genes do.

Here is an article that describes a non-canonical display of the Terminase, large subunits parts. Zhao H, Christensen TE, Kamau YN, Tang L. Structures of the phage Sf6 large terminase provide new insights into DNA translocation and cleavage. Proceedings of the National Academy of Sciences of the United States of America. 2013;110(20):8075-8080. doi:10.1073/pnas.1301133110.

The small terminase is more elusive, and sometimes we cannot find it. It can also be part of the large terminase gene.

debbie

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Terminase, small subunit in right arm