Stated another way the error frequency in base

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: r way… the error frequency in base pairing is 5 x 10-10 per base pairing event. Insertion or deletion mutations • Errors in DNA replication: addition or loss of nucleotides • Occur at regions in DNA where nucleotide pair repeated several times • During replication either the template strand or newly synthesize DNA strand “slips” • Template strand slips: Deletion, next slide • Newly synthesized strand slips: Insertion, see Fig. 5-11 Custom Text Loop held in placed by surrounding complementary base pairing New DNA New strand slips 3' 5' CGTTTT 3' GCAAAAACGT GT 5' 5' Template 3' 3' C TTT GCAAAAACGT 5' A has been copied A copied again GT Next cell division: bottom strand copied 5' 3' 5' 3' 3' C GCAAAAACGT CGTTTTTGCA GCAAAAACGT Wild-type TTTTTGCA 3' 5' 5' Next cell division: top strand copied 5' 3' CGTTTTTTGCA GCAAAAAACGT 3' 5' Insertion mutation Induced mutation Base substitution mutations Environmental chemical reacts with a base Base structure altered DNA polymerase makes a base-pairing error Mutation • Example of target site modification leading to antibiotic-resistance that can be explained by induced mutation: • Erwinia amylovora: Gram -ve rod, close relative of E. coli • Infects plant...
View Full Document

This note was uploaded on 10/25/2013 for the course MICB 201 taught by Professor Davidturner during the Fall '12 term at The University of British Columbia.

Ask a homework question - tutors are online