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Ecs, an ABC transporter of Bacillus subtilis : dual signal transduction functions affecting expression of secreted proteins as well as their secretion
Author(s) -
Leskelä Soile,
Wahlström Eva,
Hyyryläinen HanneLeena,
Jacobs Myra,
Palva Airi,
Sarvas Matti,
Kontinen Vesa P.
Publication year - 1999
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.1999.01194.x
Subject(s) - biology , cistron , bacillus subtilis , transcription (linguistics) , mutant , operon , microbiology and biotechnology , signal transduction , secretion , secretory protein , gene , biochemistry , genetics , bacteria , linguistics , philosophy
ecs is a three‐cistron operon of Bacillus subtilis , encoding proteins with similarity to the ATPase (EcsA) and hydrophobic components (EcsB) of ABC transporters. The ecsA26 point mutation was shown to cause a strong processing defect of a secreted α‐amylase precursor (preAmyQ) and of three other exoproteins. Northern analysis of the level of amyQ mRNA showed that ecsA26 also decreases amyQ transcription. This effect too was pleiotropic, as judged by a drastic decrease in the expression from an exoprotease promoter of a reporter protein. A knockout mutation of the ecsB cistron caused a processing defect similar to ecsA26 but, unlike ecsA26 , did not affect amyQ transcription. There was also no defect in transcription in the ecsA ecsB double mutant. Thus, an intact ecsB product was required for the downregulation of amyQ by the mutant ecsA . These results suggest a dual regulatory function for Ecs, in which Ecs, possibly as part of a signal transduction mechanism, regulates some component(s) of the protein secretion apparatus as well as secretory protein transcription in a co‐ordinated fashion.