The official website of the HHMI Science Education Alliance-Phage Hunters Advancing Genomics and Evolutionary Science program.

Welcome to the forums at Please feel free to ask any questions related to the SEA-PHAGES program. Any logged-in user may post new topics and reply to existing topics. If you'd like to see a new forum created, please contact us using our form or email us at

Minor tail protein in the far left arm of CS3 phages?

| posted 30 Sep, 2021 21:26

This is Ping An at University of Pittsburgh. I need some help understanding the minor tail protein gene called in the left arm of CS3 phages. The phamerator image in the attached slide should help to clarify which minor tail protein genes (highlighted in red ovals) are being discussed below.
I've noticed that a minor tail protein was called immediately downstream of the portal protein in the left arm in several CS3 phages including Guillaume, Newt and Lucker. This seems puzzling to me since they are not cluster A phages in which you may expect minor tail proteins in the left arm.
It turns out that the minor tail protein genes in the above 3 phages have high nucleotide similarity to gene 34 (with the minor tail protein function assignment) in phage Asapag of cluster DN1.
My questions are, first, should gene 34 in Asapag be assigned the function as minor tail protein? second, if Asapag gene 34 indeed should be called a minor tail protein, then can we assign the same to the similar genes in the left arm of CS3 phages?

Thank you in advance for your help and insights! I look forward to your response!
| posted 01 Nov, 2021 01:06
Sorry for the delay in this response. I think that the hits to levanase and hydrolase suggest that this could be a minor tail protein. It is not in a canonical location so this gets a bit tricky to call. Howver, becsuse it is very similar to BENtherdunthat_gp35 that is in a more canonical space makes me think that it could indeed be a minor tail.
Login to post a reply.