GO_REF:0000043

Gene Ontology annotation based on UniProtKB/Swiss-Prot keyword mapping

PMID:27193680

Structure of the T4 baseplate and its function in triggering sheath contraction.

Presents the atomic structure of the ~6-MDa T4 baseplate in pre- and post-attachment states, resolving the homohexameric gp54 ring atop gp48 at the baseplate-tail tube junction.

"Here we present the atomic structure of the approximately 6-megadalton bacteriophage T4 baseplate in its pre- and post-host attachment states and explain the events that lead to sheath contraction in atomic detail."

file:BPT4/54/54-uniprot.txt

UniProtKB record for P13341 (54_BPT4)

gp54 forms a homohexameric ring constituting the second annulus of the tail tube at the baseplate-tail tube junction, interacting with gp48, gp19, and the first layer of gp18 sheath subunits to initiate tail tube polymerization.

"Baseplate protein that forms, together with gp48, the baseplate-tail tube junction. The tail tube first 2 annuli are formed by gp48 and gp54, which are in continuation of the spike complex."

file:BPT4/54/54-deep-research-falcon.md

Deep research summary for Bacteriophage T4 gene 54 (gp54)

gp54 is a structural assembly initiator with fold similarity to the tail tube protein that, together with gp48 and gp29, nucleates polymerization of gp19 into the tail tube.

"Across authoritative sources, gp54 is best defined as a structural assembly initiator/adaptor rather than an enzyme: gp54 (together with gp48) forms a platform at the top of the baseplate hub that initiates oligomerization/polymerization of gp19 tail-tube subunits."