Why in the News?

“Klebsiella pneumoniae” bacteria might employ a newly discovered protein called “Neo” to halt bacteriophage infections.

About Neo Protein

Discovery Details: Researchers, led by Stephen Tang and Samuel Sternberg, reported the discovery of Neo in a 2023 preprint paper on bioRxiv, while investigating Klebsiella pneumoniae.
Neo’s Defense Strategy: Bacteria employ diverse immune systems to fend off viral infections, including defense-associated reverse transcriptase (DRT) systems, which Neo is a part of.
- DRT-2 System: This system involves de novo gene synthesis via rolling-circle reverse transcription (RT) of a non-coding RNA (ncRNA).
- Operational Process: In uninfected cells, the ncRNA and RT enzyme catalyze the synthesis of a repetitive single-stranded cDNA.
- Activation by Phage: Phage presence triggers the synthesis of the second-strand cDNA, resulting in long double-stranded DNA.
- Role of Neo Protein: The translation of this double-strand cDNA produces the Neo protein, which induces potent growth arrest (cell dormancy), thereby protecting the bacterial population from phage proliferation.

Potential Applications: Neo represents a promising tool for controlling viral infections, holding significance in both biotechnology and medicine.
Evolutionary Connections: Neo’s discovery sheds light on the shared evolutionary history and functional mechanisms of retroelements in the human genome and bacterial reverse transcriptases.
Technological Influence: Bacterial reverse transcriptases, predecessors of their eukaryotic counterparts, share analogous mechanisms and have revolutionized molecular biology research methods.

Reverse transcription, the conversion of RNA into DNA, is facilitated by the enzyme reverse transcriptase.
Discovered by Howard Temin and David Baltimore in 1970, reverse transcriptase has transformed molecular biology research, particularly in studying RNA viruses like HIV.
- Practical Applications: Reverse transcriptase is instrumental in gene cloning, PCR techniques, genome analysis, and viral load detection in diagnostics, such as the case of SARS-2, aiding in virus surveillance, healthcare management, and vaccine development efforts.

[2019] What is Cas9 protein that is often mentioned in the news?

(a) A molecular scissors used in targeted gene editing.

(b) A biosensor used in the accurate detection of pathogens in patients.

(d) A herbicidal substance synthesized in genetically modified crops.