HAMAP rule MF_04104

General rule information [?]

Accession	MF_04104
Dates	18-OCT-2016 (Created) 1-DEC-2022 (Last updated, Version 9)
Name	HOLIN_T4
Scope(s)	Viruses Caudoviricetes
Template(s)	P06808 (HOLIN_BPT4); [ Recover all ]
Triggered by	HAMAP; MF_04104 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier	HOLIN
Protein name	RecName: Full=Holin;

Comments [?]

FUNCTION	Accumulates harmlessly in the cytoplasmic membrane until it reaches a critical concentration that triggers the formation of micron- scale pores (holes) causing host cell membrane disruption and endolysin escape into the periplasmic space. Determines the precise timing of host cell lysis. Regulated by specific antiholins that somehow sense superinfections and then delay lysis. Participates with the endolysin and spanin proteins in the sequential events which lead to the programmed host cell lysis releasing the mature viral particles from the host cell.
SUBUNIT	Homomultimer. Heterotetramer composed of 2 holin and 2 antiholin. The holin-antiholin complex binds dsDNA. Interacts (via C- terminus) with antiholin (via C-terminus); this interaction blocks the holin homomultimerization and delays host cell lysis. Interacts (via N- terminus) with the lysis inhibition accessory protein rIII; this interaction stabilizes the holin-antiholin complex thereby resulting in a robust block of the hole formation.
SUBCELLULAR LOCATION	Host cell inner membrane; Single-pass type II membrane protein; Periplasmic side. Note=Classified as a class III holin.
DOMAIN	The C-terminus serves, in association with the antiholin, as a DNA sensor for lysis inhibition under superinfection conditions.
case <FTTag:disulf>
PTM	Disulfide bond is required for functionality.
end case
SIMILARITY	Belongs to the T4likevirus holin family.

Keywords [?]

Gene Ontology [?]

GO:0140911; Molecular function:pore-forming activity

GO:0016020; Cellular component:membrane

GO:0020002; Cellular component:host cell plasma membrane

Cross-references [?]

Pfam	PF11031; Phage_holin_T; 1;

Features [?]

From: HOLIN_BPT4 (P06808)

Key

From

Description

Tag

Condition

FTGroup

TOPO_DOM

Nter

/note="Cytoplasmic"

TRANSMEM

/note="Helical; Signal-anchor for type II membrane protein"

TOPO_DOM

Cter

/note="Periplasmic"

DISULFID

175

207

disulf

C-x*-C

Additional information [?]