Domains of invasion organelle proteins from apicomplexan parasites are homologous with the Apple domains of blood coagulation factor XI and plasma pre‐kallikrein and are members of the PAN module superfamily

FEBS Letters

Tomley, Fiona M.¹  McVey, John H.²  Nugent, Philip G.²  Brown, Philip J.¹  Gill, Andrew C.¹ 

[1] Institute for Animal Health, Compton Laboratory, Compton, Newbury, Berkshire RG20 7NN, UK;Haemostasis Group, MRC Clinical Sciences Centre, ICSM, London W12 0NN, UK

关键词: N-terminal domain of plasminogen module;    Apple domain;    Apicomplexa;    Microneme;    Mass spectrometry;    A-domain;    Apple domain;    PAN module;    N-terminal domain of plasminogen module;    FXI;    coagulation factor XI;    PK;    plasma pre-kallikrein;   

DOI  :  10.1016/S0014-5793(01)02424-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Micronemes are specialised organelles, found in all apicomplexan parasites, which secrete molecules that are essential for parasite attachment to and invasion of host cells. Regions of several microneme proteins have sequence similarity to the Apple domains (A-domains) of blood coagulation factor XI (FXI) and plasma pre-kallikrein (PK). We have used mass spectrometry on a recombinant-expressed, putative A-domain from the microneme protein EtMIC5 from Eimeria tenella, to demonstrate that three intramolecular disulphide bridges are formed. These bridges are analogous to those that stabilise A-domains in FXI and PK. The data confirm that the apicomplexan domains are structural homologues of A-domains and are therefore novel members of the PAN module superfamily, which also includes the N-terminal domains of members of the plasminogen/hepatocyte growth factor family. The role of A-domains/PAN modules in apicomplexan parasites is not known, but their presence in the microneme suggests that they may be important for mediating protein–protein or protein–carbohydrate interactions during parasite attachment and host cell invasion.

【 授权许可】

Unknown