MCB 3020 Chapter Notes - Chapter 20: Replisome, Bacteriophage, Lysozyme
Document Summary
Bacteriophage t4: a virulent bacteriophage: phage life cycle culminates with host cell bursting, releasing virions, steps. Adsorption to receptor on e. coli outer membrane tail sheath lysozyme/central tube pierce the cell wall. Viral nucleic acid is injected into host cell through tube: temporal transcription regulated by. Alternative e. coli polymerase factors induced by virus. Early viral gene products stimulate transcription of some late viral genes. Genes with related functions are usually separated and clustered together. Early gene transcribed counterclockwise late genes transcribed clockwise. The t4 genome: a large proportion of the genome codes for replication-related products including. Synthesis of hydroxymethylcytosine (hmc), a modified nucleotide replacing cytosine in t4 dna. T4 da: hmc is then chemically modified by glucosylation. Protects t4 phage dna from e. coli restriction enzymes. Enzymes that cleave dna at specific sequences restriction is a bacterial defense mechanism used against bacteriophage infection.
