DNA-dependent RNA polymerase from the extremely halophilic archaebacterium Halococcus morrhuae

Area of Science:

• Molecular Biology
• Extremophile Research
• Archaebacterial Biochemistry

Background:

• The study focuses on the molecular machinery of extremophilic organisms.
• Understanding RNA polymerase in halophilic archaea is crucial for insights into microbial adaptation.

Purpose of the Study:

• To isolate and characterize the DNA-dependent RNA polymerase from Halococcus morrhuae.
• To investigate the enzyme's subunit composition, template preference, and response to inhibitors and stimulators.

Main Methods:

• Isolation and purification of DNA-dependent RNA polymerase from Halococcus morrhuae.
• Analysis of enzyme subunit composition using molecular weight determination.
• Assays to determine template efficiency and inhibition/stimulation patterns.

Main Results:

• A pure DNA-dependent RNA polymerase was isolated, comprising five heavy and five small subunits.
• Single-stranded DNA demonstrated the highest template efficiency.
• The enzyme was resistant to rifampicin, streptolydigin, and alpha-amanitin but sensitive to heparin for initiation.
• Glycerol and dimethyl sulfoxide significantly stimulated enzyme activity.

Conclusions:

• The isolated RNA polymerase possesses a unique structure and regulatory properties distinct from other known polymerases.
• Halococcus morrhuae RNA polymerase exhibits specific interactions with DNA templates and regulatory molecules, reflecting its adaptation to high-salt environments.