MBIO 4600 Lecture Notes - Lecture 24: Antisense Rna, Pseudoknot, Plasmid

• School: University of Manitoba
• Department: Microbiology
• Course: MBIO 4600
• Professor: Brassinga Ann

Document Summary

Scenario 1: pseudoknot formation, repy translation, repz translation, replication can occur, scenario 2, inc antisense rna binding. Example 2: colib-p9 plasmid: control of copy number via antisense rna as well as secondary structures, antisense rna inc, leader peptide repy and repz (=repa) are translationally. Regulation of transcription of the rep gene by antisense rna: staphylococcus plasmid pt181, rolling circle replication, repc initiates leading strand synthesis at oriv. Inactive each time dna replicates rate-limiting for replication: scenario 1. No repc transcription, and thus no translation. Regulation by coupling: iteron plasmids, several repeats of sequence (i. e. iteron) in oriv region. 3-7 copies of 17-22 bp long iterons. Psc101: repa regulates copy number through r1, r2, and r3 iteron, negative transcriptional autoregulation of repa, coupling of plasmids mechanism coupling hypothesis . If high concentration of plasmid no replication; plasmids coupled. Prevent loss (i. e. curing) of plasmids from cells.