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head-to-tail stopper

| posted 24 Mar, 2023 16:35
I’m currently working on phage Culver in the CQ1 cluster and am having an issue with calling the function of gene 37 (15874-16227). Significant BLASTp matches show a mix of head closure proteins (not listed on official function list), hypothetical proteins, and head-to-tail stopper proteins. HHPred populates multiple significant hits, one of which aligns to SPP1 gp16. In the official functions list notes for head-to-tail stopper we much “must have an HHPRED alignment to one of the following crystal structures: SPP1 16 (5A21 chain E or F in the macromolecular complex”. We do not have that match, however we do have a match with 7ZAW_1 Head completion protein gp16 of Bacteriophage SPP1, Head completion proteins, Connector Compex. Based on this, can we call this “head-to-tail stopper”?
| posted 29 Mar, 2023 12:54
I am willing to call this a head-to-tail stopper because the first hit is to gp20 of L5. while we have not updated the label of that gene, when you HHpred it, it is a good hit to the 5A21_G project, which is the gene that we are assigning the function had-to-tail stopper.
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