Conserved Site

Antenna complex, beta subunit, conserved site (IPR023623)

Short name: Antenna_beta_CS


The antenna complexes of photosynthetic bacteria function as light-harvesting systems that absorb light and transfer the excitation energy to the reaction centres. The antenna complexes usually comprise 2 polypeptides (alpha- and beta-chains), 2-3 bacteriochlorophyll molecules and some carotenoids [PMID: 1577009, PMID: 1460542]. The alpha- and beta-chains are small proteins of 40-70 residues. Each has an N-terminal hydrophilic cytoplasmic domain, a single transmembrane (TM) region, and a small C-terminal hydrophilic periplasmic domain. In both chains, the TM domain houses a conserved His residue, presumed to be involved in binding the magnesium atom of a bacteriochlorophyll group. The beta-chains are characterised by a further histidine at the C-terminal extremity of the cytoplasmic domain, which is also thought to be involved in bacteriochlorophyll binding.

This entry represents a conserved site in the beta subunit that includes the histidine residues thought to be involved in bacteriochlorophyll binding.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns