Check out the genes upstream of the tail assembly chaperone (in Adaia, they are genes 8 and 9). it is easy to see that gene 8 is the major tail (HHPred results). Remember that it matches the SPP1 crystal structure project. This gene matches "H" which is a major tail protein and NOT the portal or head-to-tail connector complex protein. I am wondering if there is a legitimate programmed frameshift with this protein. See Baranov, et al 2006 where a major tail +1 ribosomal slippage is cited in a Listeria phage, PSA. While our slippery sequence doesn't match the one found in that major tail protein, our major tail protein - gp 8 - is 140 amino acids, while gp9 is 130 amino acids. A quick look at other major tail proteins across the actinobacteriophages, I have found gp sizes of 170 - 282 amino acids. Just wondering if the major tail protein is in 2 genes in this case. Further review is needed.
Edited 21 Jun, 2018 16:27