Characterization of the Overlapping Promoters of nolB and nolW, Two Soybean Cultivar Specificity Genes from Rhizobium fredii Strain USDA257

The transcripts of nolW and nolB, two divergently oriented cultivar specificity genes of Rhizobium fredii strain USDA257, are known to be initiated 14 bp apart from promoters that face one another. We show here that expression of nolB is dependent both on induction with flavonoid signals and on the regulatory gene, nodD1. Expression of nolW is constitutive and independent of flavonoids and nodD1. Normal expression of nolB is retained with a promoter that extends only 61 bp upstream of the transcript start site, but it is lost if an additional 24 bp are removed. Substantial expression of nolW is retained with a promoter that contains only 34 bp of DNA upstream from the transcript initiation site. The dual control region for the two genes is thus only about 109 bp in length.

Download Full-text

Cloning and Characterization of a Chromosomal Class C β-Lactamase and Its Regulatory Gene in Laribacter hongkongensis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.5.1957-1964.2005 ◽

2005 ◽

Vol 49 (5) ◽

pp. 1957-1964 ◽

Cited By ~ 23

Author(s):

Susanna K. P. Lau ◽

Pak-leung Ho ◽

Maria W. S. Li ◽

Hoi-wah Tsoi ◽

Raymond W. H. Yung ◽

...

Keyword(s):

Genomic Dna ◽

Southern Hybridization ◽

Regulatory Gene ◽

Kinetic Properties ◽

Restriction Fragments ◽

Regulatory Systems ◽

Laribacter Hongkongensis ◽

Consensus Motifs ◽

Class C

ABSTRACT Laribacter hongkongensis, a newly discovered bacterium recently shown to be associated with community-acquired gastroenteritis, is generally resistant to most β-lactams except the carbapenems. We describe the cloning and characterization of a novel chromosomal class C β-lactamase and its regulatory gene in L. hongkongensis. Two genes, ampC and ampR, were cloned by inserting restriction fragments of genomic DNA from L. hongkongensis strain HLHK5 into pBK-CMV to give the recombinant plasmid pBK-LHK-5. The ampR and ampC genes and their promoters were divergently oriented, with the ampR gene immediately upstream of the ampC gene and an intercistronic Lys-R motif, typical of inducible ampC-ampR regulatory systems. The deduced amino acid sequence of the cloned AmpC β-lactamase (pI 8.1) contained consensus motifs characteristic of class C β-lactamases but had identities no greater than 46% to known class C β-lactamases. The kinetic properties of this AmpC were also compatible with those of a class C β-lactamase. PCR of 20 clinical isolates of L. hongkongensis, including HLHK5, showed the presence of both ampC and ampR genes in all isolates. Southern hybridization suggested that the ampC gene of HLHK5 was chromosomally encoded. Subcloning experiments showed that the expression of the ampC gene of HLHK5 was regulated by its ampR gene, which acts as a repressor. The β-lactamase characterized from strain HLHK5 was named LHK-5 (gene, bla LHK-5) and represents the first example of AmpC β-lactamase in the β subdivision of proteobacteria.

Download Full-text

Characterization of the pcaR regulatory gene from Pseudomonas putida, which is required for the complete degradation of p-hydroxybenzoate.

Journal of Bacteriology ◽

10.1128/jb.176.18.5771-5779.1994 ◽

1994 ◽

Vol 176 (18) ◽

pp. 5771-5779 ◽

Cited By ~ 46

Author(s):

S Romero-Steiner ◽

R E Parales ◽

C S Harwood ◽

J E Houghton

Keyword(s):

Pseudomonas Putida ◽

Regulatory Gene ◽

Complete Degradation

Download Full-text

Structure of the rainbow trout metallothionein B gene and characterization of its metal-responsive region

Molecular and Cellular Biology ◽

10.1128/mcb.8.10.4469-4476.1988 ◽

1988 ◽

Vol 8 (10) ◽

pp. 4469-4476

Author(s):

M Zafarullah ◽

K Bonham ◽

L Gedamu

Keyword(s):

Rainbow Trout ◽

Cell Line ◽

Binding Sites ◽

Transcription Initiation ◽

Hepatoma Cell ◽

Initiation Site ◽

Hepatoma Cell Line ◽

Flanking Region ◽

Chloramphenicol Acetyltransferase Gene

The trout metallothionein (MT) genes consist of two members. We describe the structure of the first fish MT (tMT-B) gene which shows an overall resemblance but some remarkable differences with mammalian MT genes. The similarities included (i) tripartite structure of the gene, (ii) conservation of cysteine residues, and (iii) a TATAAA signal and two copies of metal-responsive elements (MREs). The differences consisted of (i) an AT-rich tMT-B promoter compared with highly GC-rich mammalian MT promoters and (ii) a lack of SP1-binding sites in the tMT-B promoter. Functional analysis of the tMT-B 5'-flanking region following fusion with the bacterial chloramphenicol acetyltransferase gene and its transfection into the rainbow trout hepatoma cell line revealed that sequences from positions -600 to +8 are sufficient for regulation by metals. Further deletion analyses of this fragment suggested that a minimum of 100 nucleotides upstream of the transcription initiation site are required for induction by cadmium and zinc. The tMT-B promoter was also functional in the human hepatoblastoma cell line, suggesting that an MT regulatory factor(s) is conserved in phylogenetically distant species like humans and fish.

Download Full-text

Primary Pulmonary Pleomorphic Adenoma

Archives of Pathology & Laboratory Medicine ◽

10.5858/2003-127-0621-pppa ◽

2003 ◽

Vol 127 (5) ◽

pp. 621-622

Author(s):

Keng Leong Ang ◽

Venkata Ramana Dhannapuneni ◽

William Ellis Morgan ◽

Irshad Nabi Soomro

Keyword(s):

Pleomorphic Adenoma ◽

Regulatory Gene ◽

Proliferation Index ◽

Complete Excision ◽

Long Term Follow Up ◽

Uncommon Condition ◽

P16 Ink4a

Abstract Primary pleomorphic adenoma of the lung is an uncommon condition. We present a case of primary pulmonary pleomorphic adenoma and its immunohistologic features. The presence of immunoreactivity to both anticytokeratin and antivimentin antibodies for its epithelial components is suggestive of a primary pulmonary lesion. Its high proliferation index and its immunoreactivity to tumor regulatory gene p16(INK4A) are features that, to our knowledge, have not been reported previously. They may have a role in the frequent recurrence of these tumors many years after their apparently complete excision. Detailed genetic investigation and long-term follow-up of this rare tumor will aid in the characterization of its biologic profile.

Download Full-text