Properties of arsenite efflux permeases (Acr3) from Alkaliphilus metalliredigens and Corynebacterium glutamicum.
Members of the Acr3 family of arsenite permeases confer resistance to trivalent arsenic by extrusion from cells, with members in every phylogenetic domain. In this study bacterial Acr3 homologues from Alkaliphilus metalliredigens and Corynebacterium glutamicum were cloned and expressed in Escherichia coli. Modification of a single cysteine residue that is conserved in all analyzed Acr3 homologues resulted in loss of transport activity, indicating that it plays a role in Acr3 function. The results of treatment with thiol reagents suggested that the conserved cysteine is located in a hydrophobic region of the permease. A scanning cysteine accessibility method was used to show that Acr3 has 10 transmembrane segments, and the conserved cysteine would be predicted to be in the fourth transmembrane segment.
Fu
Hseuh-Liang
HL
Department of Biochemistry and Molecular Biology, Wayne State University, School of Medicine, Detroit, Michigan 48201, USA.
Meng
Yuling
Y
Ordóñez
Efrén
E
Villadangos
Almudena F
AF
Bhattacharjee
Hiranmoy
H
Gil
José A
JA
Mateos
Luís M
LM
Rosen
Barry P
BP
D000595:Amino Acid Sequence; D053501:Arsenite Transporting ATPases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D018053:Arsenites / Q000032:analysis / Q000378:metabolism*; D003001:Cloning, Molecular; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics; D003545:Cysteine / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006094:Gram-Positive Bacteria / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D017354:Point Mutation; D017433:Protein Structure, Secondary; D013439:Sulfhydryl Reagents
D018053:Arsenites; D013439:Sulfhydryl Reagents; D053501:Arsenite Transporting ATPases; D003545:Cysteine; C015001:arsenite