Summary: PQ loop repeat
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PQ loop repeat Provide feedback
Members of this family are all membrane bound proteins possessing a pair of repeats each spanning two transmembrane helices connected by a loop . The PQ motif found on loop 2 is critical for the localisation of cystinosin to lysosomes . However, the PQ motif appears not to be a general lysosome-targeting motif. It is thought likely to possess a more general function. Most probably this involves a glutamine residue .
Ponting CP, Mott R, Bork P, Copley RR; , Genome Res 2001;11:1996-2008.: Novel protein domains and repeats in Drosophila melanogaster: insights into structure, function, and evolution. PUBMED:11731489 EPMC:11731489
Cherqui S, Kalatzis V, Trugnan G, Antignac C; , J Biol Chem 2001;276:13314-13321.: The targeting of cystinosin to the lysosomal membrane requires a tyrosine-based signal and a novel sorting motif. PUBMED:11150305 EPMC:11150305
External database links
This tab holds annotation information from the InterPro database.
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- the number of sequences which exhibit this architecture
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This example describes an architecture with one
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EGFdomains, and finally a single
- the UniProt description of the protein sequence
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The clan forms a large and diverse family of proteins with seven transmembrane helices, common topology and, most likely, similar function. Their coding genes exist in all eukaryota and in several prokaryota. Some are responsible for metabolic diseases (cystinosis, congenital disorder of glycosylation), others are candidate genes for genetic disorders (cleft lip and palate, certain forms of cancer) or solute uptake and efflux (SWEETs) and many have not yet been assigned a function. Comparison with the properties of well-annotated clan members suggests that the proteins could be involved in protein trafficking and serve as cargo receptors in vesicle trafficking .
The clan contains the following 5 members:ER_lumen_recept LAB_N MPC MtN3_slv PQ-loop
We make a range of alignments for each Pfam-A family:
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Curation and family details
|Seed source:||TIGRFAMs (release 2.0);|
|Author:||TIGRFAMs, Finn RD|
|Number in seed:||255|
|Number in full:||3702|
|Average length of the domain:||59.40 aa|
|Average identity of full alignment:||21 %|
|Average coverage of the sequence by the domain:||35.09 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||9|
|Download:||download the raw HMM for this family|
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