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50  structures 3540  species 0  interactions 16358  sequences 623  architectures

Clan: 4HB_MCP (CL0457)


Aspartate chemoreceptor, signal-transduction ligand-binding Add an annotation

This superfamily is characterised by a four-helix bundle structure that forms a ubiquitous sensory module in prokaryotic signal-transduction. The 4HB_MCP is always found between two predicted transmembrane helices indicating that it detects only extracellular signals. In many cases the domain is associated with a cytoplasmic HAMP domain suggesting that most proteins carrying the bundle might share the mechanism of transmembrane signalling which is well-characterised in E coli chemoreceptors.

This clan contains 4 families and the total number of domains in the clan is 16358. The clan was built by L Ulrich and P Coggill.

Literature references

  1. Ulrich LE, Zhulin IB;, Bioinformatics. 2005;21:iii45-iii48.: Four-helix bundle: a ubiquitous sensory module in prokaryotic signal transduction. PUBMED:16306392 EPMC:16306392


This clan contains the following 4 member families:


External database links

Domain organisation

Below is a listing of the unique domain organisations or architectures from this clan. More...

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The table below shows the number of occurrences of each domain throughout the sequence database. More...

Pfam family Num. domains Alignment
4HB_MCP_1 (PF12729) 10055 (61.5%) View
CHASE3 (PF05227) 4362 (26.7%) View
TarH (PF02203) 1680 (10.3%) View
HBM (PF16591) 261 (1.6%) View
Total: 4 Total: 16358 Clan alignment

Please note: Clan alignments can be very large and can cause problems for some browsers. Read the note above before viewing.

Family relationships

This diagram shows the relationships between members of this clan. More...

Species distribution

Tree controls


This tree shows the occurrence of the domains in this clan across different species. More...



For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the MSD group, to allow us to map Pfam domains onto UniProt three-dimensional structures. The table below shows the mapping between the Pfam families in this clan, the corresponding UniProt entries, and the region of the three-dimensional structures that are available for that sequence.

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