SUPERFAMILY 1.73 HMM library and genome assignments server


Thyroglobulin type-1 domain superfamily

SCOP classification
Root:   SCOP hierarchy in SUPERFAMILY [ 0] (11)
Class:   Small proteins [ 56992] (85)
  Usually dominated by metal ligand, heme, and/or disulfide bridges
Fold:   Thyroglobulin type-1 domain [ 57609]
  disulfide-rich, alpha+beta
Superfamily:   Thyroglobulin type-1 domain [ 57610]
Families:   Thyroglobulin type-1 domain [ 57611] (2)
  Pfam 00086


Superfamily statistics
Genomes (91) UniProt 15.0 PDB chains (SCOP 1.73)
Domains 1,824 807 2
Proteins 1,140 504 2


Functional annotation
General category Processes_IC
Detailed category Proteases

Function annotation of SCOP domain superfamilies
InterPro annotation
Cross references IPR000716 SSF57610 Protein matches
Abstract

Thyroglobulin (Tg) is a large glycoprotein specific to the thyroid gland and is the precursor of the iodinated thyroid hormones thyroxine (T4) and triiodothyronine (T3). The N-terminal section of Tg contains 10 repeats of a domain of about 65 amino acids which is known as the Tg type-1 repeat [PubMed3595599, PubMed8797845]. Such a domain has also been found as a single or repeated sequence in the HLA class II associated invariant chain [PubMed3038530]; human pancreatic carcinoma marker proteins GA733-1 and GA733-2 [PubMed2333300]; nidogen (entactin), a sulphated glycoprotein which is widely distributed in basement membranes and that is tightly associated with laminin; insulin-like growth factor binding proteins (IGFBP) [PubMed1709161]; saxiphilin, a transferrin-like protein from Rana catesbeiana (Bull frog) that binds specifically to the neurotoxin saxitoxin [PubMed8146142]; chum salmon egg cysteine proteinase inhibitor, and equistatin, a thiol-protease inhibitor from Actinia equina (sea anemone) [PubMed9153250]. The existence of Thyr-1 domains in such a wide variety of proteins raises questions about their activity and function, and their interactions with neighbouring domains. The Thyr-1 and related domains belong to MEROPS proteinase inhibitor family I31, clan IX.

Equistatin from A. equina is composed of three Thyr-1 domains; as with other proteins that contains Thyr-1 domains, the thyropins, they bind reversibly and tightly to cysteine proteases (inhibitor family C1). In equistatin inhibition of papain is a function of domain-1. Unusually domain-2 inhibits cathepsin D, an aspartic protease (inhibitor family A1) and has no activity against papain. Domain-3, does not inhibit either papain or cathepsin D, and its function or its target peptidase has yet to be determined [PubMed9153250, PubMed12650938].


InterPro database

PDBeMotif information about ligands, sequence and structure motifs
Cross references PDB entries
Ligand binding statistics
Nucleic-acid binding statistics
Occurrence of secondary structure elements
Occurrence of small 3D structural motifs

PDBeMotif resource

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Internal database links

Browse genome assignments for this superfamily. The SUPERFAMILY hidden Markov model library has been used to carry out SCOP domain assignments to all genomes at the superfamily level.


Alignments of sequences to 2 models in this superfamily are available by clicking on the 'Alignments' icon above. PDB sequences less than 40% identical are shown by default, but any other sequence(s) may be aligned. Select PDB sequences, genome sequences, or paste in or upload your own sequences.


Browse and view proteins in genomes which have different domain combinations including a Thyroglobulin type-1 domain domain.


Examine the distribution of domain superfamilies, or families, across the major taxonomic kingdoms or genomes within a kingdom. This gives an immediate impression of how superfamilies, or families, are restricted to certain kingdoms of life.


Explore domain occurrence network where nodes represent genomes and edges are domain architectures (shared between genomes) containing the superfamily of interest.

There are 2 hidden Markov models representing the Thyroglobulin type-1 domain superfamily. Information on how the models are built, and plots showing hydrophobicity, match emmission probabilities and insertion/deletion probabilities can be inspected.


Jump to [ Top of page · SCOP classification · InterPro annotation · PDBeMotif links · Functional annotation · Internal database links ]