Êtes-vous un étudiant de l'EPFL à la recherche d'un projet de semestre?
Travaillez avec nous sur des projets en science des données et en visualisation, et déployez votre projet sous forme d'application sur Graph Search.
Concept
Globine
Résumé
The globins are a superfamily of heme-containing globular proteins, involved in binding and/or transporting oxygen. These proteins all incorporate the globin fold, a series of eight alpha helical segments. Two prominent members include myoglobin and hemoglobin. Both of these proteins reversibly bind oxygen via a heme prosthetic group. They are widely distributed in many organisms.
Globin superfamily members share a common three-dimensional fold. This 'globin fold' typically consists of eight alpha helices, although some proteins have additional helix extensions at their termini. Since the globin fold contains only helices, it is classified as an all-alpha protein fold.
The globin fold is found in its namesake globin families as well as in phycocyanins. The globin fold was thus the first protein fold discovered (myoglobin was the first protein whose structure was solved).
The eight helices of the globin fold core share significant nonlocal structure, unlike other structural motifs in which amino acids close to each other in primary sequence are also close in space. The helices pack together at an average angle of about 50 degrees, significantly steeper than other helical packings such as the helix bundle. The exact angle of helix packing depends on the sequence of the protein, because packing is mediated by the sterics and hydrophobic interactions of the amino acid side chains near the helix interfaces.
Globins evolved from a common ancestor and can be divided into three lineages:
Family M (for myoglobin-like) or F (for FHb-like), which has a typical 3/3 fold.
Subfamily FHb, for flavohaemoglobins. Chimeric.
Subfamily SDgb, for single-domain globins (not to be confused with SSDgb).
Family S (for sensor-like), again with a 3/3 fold.
Subfamily GCS, for Globin-coupled sensors. Chimeric.
Subfamily PGb, for protoglobins. Single-domain.
Subfamily SSDgb, for sensor single-domain globins.
Family T (for truncated), with a 2/2 fold All subfamilies can be chimeric, single-domain, or tandemly linked.
Subfamily TrHb1 (also T1 or N).
Source officielle
À propos de ce résultat
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.