Bacterial secretion chaperones.
Many Gram-negative bacteria are able to invade hosts by translocation of effectors directly into target cells in processes usually mediated by two very complex secretion systems (SSs), named type III (T3) and type IV (T4) SSs. These syringe-needle injection devices work with intervention of specialized secretion chaperones that, unlike traditional molecular chaperones, do not assist in protein folding and are not energized by ATP. Controversy still surrounds secretion chaperones primary role, but we can say that these chaperones act as: (i) bodyguards to prevent premature aggregation, or as (ii) pilots to direct substrate secretion through the correct secretion system. This family of chaperones does not share primary structure similarity but amazingly equal 3D folds. This mini review has the intent to present updated structural and functional data for several important secretion chaperones, either alone or in complex with their cognate substrates, as well to report on the common features and roles of T3, T4 and flagellar chaperones.
Chemical Biology Laboratory, Department of Organic Chemistry, Chemistry Institute, State University of Campinas, P.O. Box 6154, Campinas, S.P. 13083-970, Brazil.
Juliana
J
Fattori
Alessandra
A
Prando
Adriana Martini
AM
Martins
Fábio Henrique dos Santos
FH
Rodrigues
Ljubica
L
Tasic
D058947:Bacterial Secretion Systems / Q000502:physiology*; D005407:Flagella / Q000502:physiology; D006090:Gram-Negative Bacteria / Q000502:physiology*; D018832:Molecular Chaperones / Q000737:chemistry / Q000502:physiology*; D011487:Protein Conformation
D058947:Bacterial Secretion Systems; D018832:Molecular Chaperones