PMID- 1834913
OWN - NLM
STAT- MEDLINE
DCOM- 19911213
LR  - 20240109
IS  - 0950-382X (Print)
IS  - 0950-382X (Linking)
VI  - 5
IP  - 7
DP  - 1991 Jul
TI  - The mdoA locus of Escherichia coli consists of an operon under osmotic control.
PG  - 1745-53
AB  - In Escherichia coli, the 5 kb mdoA locus is involved in the osmotically 
      controlled biosynthesis of periplasmic membrane-derived oligosaccharides (MDOs). 
      The structure of this locus was analysed by in vitro cassette insertion, 
      transposon mutagenesis, and gene-fusion analysis. A 'neo' cassette, derived from 
      the neomycin phosphotransferase II region of transposon Tn5, was inserted into 
      mdoA, borne by a multicopy plasmid. This plasmid was shown to complement two 
      previously described mdoA mutations, depending on the orientation of the 
      exogenous gene. Thus, the gene altered by these mutations could be expressed 
      under the control of the exogenous promoter. Moreover, the 'neo' cassette 
      inactivated another, uncharacterized, mdo gene, because when this insertion was 
      transferred into the chromosome MDO synthesis was abolished. The existence of a 
      second gene was confirmed by complementation analysis with a collection of Tn1000 
      insertions into mdoA. Two groups were defined, and the two genes are organized 
      into an operon (mdoGH). This conclusion was reached because Tn1000 insertions in 
      the first gene displayed a polar effect on the expression of the second gene. An 
      active gene fusion was obtained on a multicopy plasmid between the beginning of 
      mdoH and lacZ. The hybrid beta-galactosidase activity followed the same 
      osmotically controlled response as that described for of MDO synthesis. This 
      regulation was unaffected by the presence, or absence, of MDOs in the periplasm. 
      Finally, the amount of mdoA-specific mRNAs, determined by dot blot hybridization, 
      decreased when the osmolarity of the growth medium increased.
FAU - Lacroix, J M
AU  - Lacroix JM
AD  - Institute de Microbiologie, URA 1354 CNRS, Universite Paris-Sud, Orsay, France.
FAU - Loubens, I
AU  - Loubens I
FAU - Tempete, M
AU  - Tempete M
FAU - Menichi, B
AU  - Menichi B
FAU - Bohin, J P
AU  - Bohin JP
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Mol Microbiol
JT  - Molecular microbiology
JID - 8712028
RN  - 0 (Oligosaccharides)
RN  - 0 (RNA, Messenger)
RN  - 0 (Recombinant Fusion Proteins)
RN  - 451W47IQ8X (Sodium Chloride)
RN  - EC 2.4.1.- (Glucosyltransferases)
SB  - IM
MH  - DNA Mutational Analysis
MH  - Escherichia coli/*genetics
MH  - *Gene Expression Regulation, Bacterial
MH  - Glucosyltransferases/*genetics
MH  - Mutagenesis, Insertional
MH  - Oligosaccharides/biosynthesis/genetics/isolation & purification
MH  - Operon/genetics
MH  - *Osmotic Pressure
MH  - Plasmids/genetics
MH  - RNA, Messenger/biosynthesis
MH  - Recombinant Fusion Proteins
MH  - Restriction Mapping
MH  - Sodium Chloride/pharmacology
MH  - Transcription, Genetic
EDAT- 1991/07/01 00:00
MHDA- 1991/07/01 00:01
CRDT- 1991/07/01 00:00
PHST- 1991/07/01 00:00 [pubmed]
PHST- 1991/07/01 00:01 [medline]
PHST- 1991/07/01 00:00 [entrez]
AID - 10.1111/j.1365-2958.1991.tb01924.x [doi]
PST - ppublish
SO  - Mol Microbiol. 1991 Jul;5(7):1745-53. doi: 10.1111/j.1365-2958.1991.tb01924.x.