DIFFERENTIAL EXPRESSION OF 2 SIDEROPHORE-DEPENDENT IRON-ACQUISITION PATHWAYS IN ERWINIA-CHRYSANTHEMI-3937 - CHARACTERIZATION OF A NOVEL FERRISIDEROPHORE PERMEASE OF THE ABC TRANSPORTER FAMILY

被引:42
作者
MAHE, B [1 ]
MASCLAUX, C [1 ]
RAUSCHER, L [1 ]
ENARD, C [1 ]
EXPERT, D [1 ]
机构
[1] INA PG,INRA,PATHOL VEGETALE LAB,F-75231 PARIS 05,FRANCE
关键词
D O I
10.1111/j.1365-2958.1995.mmi_18010033.x
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
In planta expression of a high-affinity iron-uptake system involving the siderophore chrysobactin in Erwinia chrysanthemi 3937 contributes greatly to invasive growth of this pathogen on its natural host, African violets. A previous study reported that global regulation by iron in this strain was mediated at the transcriptional level via the cbr locus which, when inactivated by insertional mutation, prevents the chrysobactin system from being tightly repressed by FeCl3. Herein, we report the nucleotide sequence of this locus and the functional analysis of its encoded products. Sequence analysis of a 4.8 kb genomic segment of a plasmid encompassing the cbr locus and characterization of the cognate translated products made it possible to uncover a system exhibiting similarity with prokaryotic transporters implicated in the transport of iron complexes. Accordingly, the CbrA product was shown to be the periplasmic component of a permease complex also including two integral membrane proteins, CbrB and CbrC, and the ATP-binding unit CbrD. This system allowed internalization of Fe(III) when supplied to bacterial cells as (FeCl3)-Fe-59 or Fe-59 dicitrate, via complexation to a second siderophore recently detected in strain 3937. Most notably, we demonstrate that this second siderophore-mediated iron-acquisition system is operational in bacterial cells grown in the presence of FeCl3. The regulatory effect of cbr was further assessed on a lacZ chrysobactin operon fusion indicating that the transcriptional control exerted by cbr on expression of the chrysobactin system is of homeostatic nature. In conclusion, E. chrysanthemi provides an interesting model in which iron acquisition involves an inductive process resulting in differential expression of two siderophore-mediated pathways in relation to external iron accessibility.
引用
收藏
页码:33 / 43
页数:11
相关论文
共 48 条
[1]   IDENTIFICATION AND CHARACTERIZATION OF THE EXBB, EXBD AND TONB GENES OF PSEUDOMONAS-PUTIDA WCS358 - THEIR INVOLVEMENT IN FERRIC-PSEUDOBACTIN TRANSPORT [J].
BITTER, W ;
TOMMASSEN, J ;
WEISBEEK, PJ .
MOLECULAR MICROBIOLOGY, 1993, 7 (01) :117-130
[2]   THE FERRIC-PSEUDOBACTIN RECEPTOR PUPA OF PSEUDOMONAS-PUTIDA WCS358 - HOMOLOGY TO TONB-DEPENDENT ESCHERICHIA-COLI RECEPTORS AND SPECIFICITY OF THE PROTEIN [J].
BITTER, W ;
MARUGG, JD ;
DEWEGER, LA ;
TOMMASSEN, J ;
WEISBEEK, PJ .
MOLECULAR MICROBIOLOGY, 1991, 5 (03) :647-655
[4]   REGULATION OF DIVERGENT TRANSCRIPTION FROM THE IRON-RESPONSIVE FEPB-ENTC PROMOTER-OPERATOR REGIONS IN ESCHERICHIA-COLI [J].
BRICKMAN, TJ ;
OZENBERGER, BA ;
MCINTOSH, MA .
JOURNAL OF MOLECULAR BIOLOGY, 1990, 212 (04) :669-682
[5]   PLASMID INSERTION MUTAGENESIS AND LAC GENE FUSION WITH MINI-MU BACTERIOPHAGE TRANSPOSONS [J].
CASTILHO, BA ;
OLFSON, P ;
CASADABAN, MJ .
JOURNAL OF BACTERIOLOGY, 1984, 158 (02) :488-495
[6]   IDENTIFICATION OF HYDROPHOBIC PROTEINS FEPD AND FEPG OF THE ESCHERICHIA-COLI FERRIENTEROBACTIN PERMEASE [J].
CHENAULT, SS ;
EARHART, CF .
JOURNAL OF GENERAL MICROBIOLOGY, 1992, 138 :2167-2171
[7]   ORGANIZATION OF GENES ENCODING MEMBRANE-PROTEINS OF THE ESCHERICHIA-COLI FERRIENTEROBACTIN PERMEASE [J].
CHENAULT, SS ;
EARHART, CF .
MOLECULAR MICROBIOLOGY, 1991, 5 (06) :1405-1413
[8]   CLONING AND CHARACTERIZATION OF THE FERRIC ENTEROBACTIN RECEPTOR GENE (PFEA) OF PSEUDOMONAS-AERUGINOSA [J].
DEAN, CR ;
POOLE, K .
JOURNAL OF BACTERIOLOGY, 1993, 175 (02) :317-324
[9]   METAL-ION REGULATION OF GENE-EXPRESSION - FUR REPRESSOR OPERATOR INTERACTION AT THE PROMOTER REGION OF THE AEROBACTIN SYSTEM OF PCO1V-K30 [J].
DELORENZO, V ;
GIOVANNINI, F ;
HERRERO, M ;
NEILANDS, JB .
JOURNAL OF MOLECULAR BIOLOGY, 1988, 203 (04) :875-884
[10]  
DESSEN P, 1990, COMPUT APPL BIOSCI, V6, P355