Biochemistry in Tables, Schemes and Graphs - S.D. Zhamsaranova 2009

Transmembrane Signal Transduction
Inhibitors of Template Biosynthesis

Drug

MECHANISM OF ACTION

Doxorubicin

Intercalates into DNA between Base Pairs, generates reactive oxygen species, and causes strand breaks in the macromolecule

Rifampicin

Binds to bacterial RNA polymerase and inhibits the initiation of RNA Synthesis

Melphalan

Alkylates the DNA molecule and damages its Structure

Erythromycin

Binds to the 50S ribosomal subunit and prevents translocation

Tetracycline

Attaches to the 30S ribosomal subunit and inhibits the binding of aa-tRNA to the A-site

Class="center">EFFECT OF POINT Mutations IN DNA ON The structure of THE SYNTHESIZED PROTEIN

Mutations are unrepaired Changes in the Introduction/19.html">Primary Structure of DNA that occur in the molecule As a result of defects in DNA polymerases or DNA Repair systems, or due to environmental factors from the internal and external surroundings.

Point mutations generally fall into three categories:

a) substitutions (this is the most common type of DNA damage);

б) insertions

в) deletions (or losses) of NUCLEOTIDES

Type of mutation

Changes in DNA structure

Changes in Cell/13.html">Protein Structure

Substitution:

silent (no change in codon meaning) missense (with A change in codon meaning)

Substitution of a single nucleotide in the codon

Protein remains unchanged

One amino acid is replaced by another

with The formation of a stop codon


Peptide chain synthesis is terminated at this codon, resulting in an incomplete protein

Insertion:

without a reading frame shift

Insertion of a DNA fragment consisting of 3 nucleotides or a multiple of 3

The polypeptide chain is elongated by one or more Amino Acids

with a reading frame shift

Insertion of one or more nucleotides not a multiple of 3

A peptide with a random Amino Acid Sequence is synthesized, as the meaning of all codons downstream of the mutation site is altered

Deletion:

without a reading frame shift

Loss of a DNA fragment consisting of nucleotides or a multiple of 3

The protein is shortened by one or more amino acids

with a reading frame shift

Loss of one or more nucleotides not a multiple of 3

A peptide with a random amino acid sequence is synthesized, as the meaning of all codons downstream of the mutation site is altered



Last update: 06/08/2026

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