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PROSITE documentation PDOC00251 [for PROSITE entry PS51412]

Membrane attack complex/perforin (MACPF) domain signature and profile





Description

The membrane attack complex/perforin (MACPF) domain is conserved in bacteria, fungi, mammals and plants. It was originally identified and named as being common to five complement components (C6, C7, C8-α, C8-β, and C9) and perforin. These molecules perform critical functions in innate and adaptive immunity. The MAC family proteins and perforin are known to participate in lytic pore formation. In response to pathogen infection, a sequential and highly specific interaction between the constituent elements occurs to form transmembrane channels which are known as the membrane-attack complex (MAC). Only a few other MACPF proteins have been characterized and several are thought to form pores for invasion or protection [1,2,3]. Examples are proteins from malarial parasites [4], the cytolytic toxins from sea anemones [5], and proteins that provide plant immunity [1,6]. Functionally uncharacterized MACPF proteins are also evident in pathogenic bacteria such as Chlamydia spp. [7] and Photorhabdus luminescens [2]. The MACPF domain is commonly found to be associated with other N- and C-terminal domains, such as TSP1 (see <PDOC50092>), LDLRA (see <PDOC00929>), EGF-like (see <PDOC00021>), Sushi/CCP/SCR (see <PDOC50923>), FIMAC or C2 (see <PDOC00380>). They probably control or target MACPF function [2,8]. The MACPF domain oligomerizes, undergoes conformational change, and is required for lytic activity.

The MACPF domain consists of a central kinked four-stranded antiparallel β sheet surrounded by α helices and β strands, forming two structural segments. Overall, the MACPF domain has a thin L-shaped appearance (see <PDB:2QQH; A>). MACPF domains exhibit limited sequence similarity but contain a signature [YW]-G-[TS]-H-[FY]-x(6)-G-G motif [2,3,8].

Some proteins known to contain a MACPF domain are listed below:

We developed both a pattern and a profile for the MACPF domain. Whereas the profile covers the entire MACPF domain, the pattern is based on the conserved signature of the MACPF domain.

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Last update:

November 2008 / Text revised; profile added.

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Technical section

PROSITE methods (with tools and information) covered by this documentation:

?, PS51412;   (?)

MACPF_1, PS00279; Membrane attack complex/perforin (MACPF) domain signature  (PATTERN)


Reference



PROSITE is copyrighted by the SIB Swiss Institute of Bioinformatics and distributed under the Creative Commons Attribution-NonCommercial-NoDerivatives (CC BY-NC-ND 4.0) License, see prosite_license.html.

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