SEA-PHAGES | Myo, Sypho and terminase

Link to this post \| posted 22 Jun, 2016 18:26
esmiller	I suspect the experts at Pitt know this, or there is a useful paper out there…… While the majority of mycobacteriophages are syphoviruses (non-contractile, flexible tails) there are contractile tailed myoviruses (or Syphoviridae, Myoviridae, if you prefer that). - I am aware of the C cluster myoviruses. Are there more clusters of myoviridae among the mycobacteriophages? - Is there a myoviridae phage that aligns most closely with a syphoviridae cluster and is thus an "odd one out", primarily due to its tail structure? - Has anyone compared the tail proteins of the two morphotypes of mycobacterial phages? How about a comparison of the head-tail connectors? Portal proteins? Terminases? - Finally, is there a lysogen containing a C cluster phage and does it contain a classical prophage integration? All questions piqued by topics discussed at the recent (successful!) symposium that well may be answered somewhere! Eric

Link to this post | posted 22 Jun, 2016 18:26

I suspect the experts at Pitt know this, or there is a useful paper out there……

While the majority of mycobacteriophages are syphoviruses (non-contractile, flexible tails) there are contractile tailed myoviruses (or Syphoviridae, Myoviridae, if you prefer that).

- I am aware of the C cluster myoviruses. Are there more clusters of myoviridae among the mycobacteriophages?

- Is there a myoviridae phage that aligns most closely with a syphoviridae cluster and is thus an "odd one out", primarily due to its tail structure?

- Has anyone compared the tail proteins of the two morphotypes of mycobacterial phages? How about a comparison of the head-tail connectors? Portal proteins? Terminases?

- Finally, is there a lysogen containing a C cluster phage and does it contain a classical prophage integration?

All questions piqued by topics discussed at the recent (successful!) symposium that well may be answered somewhere!

Eric

Link to this post \| posted 22 Jun, 2016 20:37
DanRussell	Hi Eric, I'll add what I know and then pass it along. - I am aware of the C cluster myoviruses. Are there more clusters of myoviridae among the mycobacteriophages? Until this past year, all known Mycobacteriophages that were Myoviridae were in Cluster C. But Hope College discovered Phrappucino, the only other Myoviridae we've collectively found. It's a Singleton. - Finally, is there a lysogen containing a C cluster phage and does it contain a classical prophage integration? Though there have been some attempts, I don't think anyone has isolated and verified a Cluster C lysogen. There are some suspected Cluster C lysogens I've heard about, but I don't think anyone's gone as far as verifying that there are integrated genomes. There's no obvious bioinformatic evidence that they'd be temperate, and all of our attempts at isolating Cluster C lysogens at Pitt have been unsuccessful. - Is there a myoviridae phage that aligns most closely with a syphoviridae cluster and is thus an "odd one out", primarily due to its tail structure? From Welkin: no. They're different enough that we haven't seen that situation yet in the Mycobacteriophages. - Has anyone compared the tail proteins of the two morphotypes of mycobacterial phages? How about a comparison of the head-tail connectors? Portal proteins? Terminases? Also from Welkin: not that we know of, at least in a comprehensive way. –Dan

Link to this post | posted 22 Jun, 2016 20:37

DanRussell

Hi Eric,

I'll add what I know and then pass it along.

- I am aware of the C cluster myoviruses. Are there more clusters of myoviridae among the mycobacteriophages?

Until this past year, all known Mycobacteriophages that were Myoviridae were in Cluster C. But Hope College discovered Phrappucino, the only other Myoviridae we've collectively found. It's a Singleton.

- Finally, is there a lysogen containing a C cluster phage and does it contain a classical prophage integration?

Though there have been some attempts, I don't think anyone has isolated and verified a Cluster C lysogen. There are some suspected Cluster C lysogens I've heard about, but I don't think anyone's gone as far as verifying that there are integrated genomes. There's no obvious bioinformatic evidence that they'd be temperate, and all of our attempts at isolating Cluster C lysogens at Pitt have been unsuccessful.

- Is there a myoviridae phage that aligns most closely with a syphoviridae cluster and is thus an "odd one out", primarily due to its tail structure?

From Welkin: no. They're different enough that we haven't seen that situation yet in the Mycobacteriophages.

- Has anyone compared the tail proteins of the two morphotypes of mycobacterial phages? How about a comparison of the head-tail connectors? Portal proteins? Terminases?

Also from Welkin: not that we know of, at least in a comprehensive way.

–Dan

Link to this post \| posted 22 Jun, 2016 20:59
esmiller	Thanks Dan. I was wondering if there was evidence of "crossing the divide", or if there were enough isolates and sequence information to address the divergence, etc.

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