The neck is the head-to-tail interface which is formed by the connector and the tail-completion proteins. The connector is formed by the portal and the head-completion proteins. (Click here for a general description of the assembly pathway of tailed bacteriophages)
adopts the structural organization of the Siphoviridae phage SPP1 neck. It is formed by a portal protein, an Ad1 (Adaptor of type 1), a Hc1 (Head-closure of type 1), a Ne1 (Neck protein of type 1) and a Tc1 (Tail-completion of type 1) proteins.
is mostly composed of siphophages (45 over 49) with a minority of myophages characterized by small genome sizes (61-150 genes). Remarkably, all the phages in this cluster infect the same class of bacteria: all the hosts belong to Firmicutes. Moreover, whatever the phages are classified as sipho- or myophages, most of them follow a tight [TermL-Portal-x(2-4)-MCP-x(0-1)-Ad1-Hc1-Ne1-Tc1] scheme suggesting a common structural organization.
(-) indicates that the genetic context is given in the reverse order. For more clarity, numbers between square brackets indicate the number of unannotated genes.
For every pair of phages sharing a given neck type and for all the components of the capsid-neck-tail module they share (out of the nine possible components described below), we calculated the corresponding HHsearch probability and sequence identity scores. The resulting scores are illustrated with colored squares whose size is proportional to the considered score (similarity scores lie in the bottom half matrix while HHsearch probabilities lie in the top half matrix). See legend below for square colors and for identity or HHsearch probability scores.
