structural gene
Học thuậtThân thiện
Definition
- Noun:
- A gene that codes for a specific protein or polypeptide: A structural gene is a segment of DNA that contains the information necessary for the synthesis of a particular functional product, such as an enzyme, structural protein, or other polypeptide chain. It is distinguished from regulatory genes, which control the expression of structural genes.
Usage and Examples
- Noun:
- The lacZ gene in E. coli is a classic example of a structural gene, as it codes for the enzyme beta-galactosidase.
- Mutations in a structural gene can lead to the production of a non-functional protein.
- The primary function of a structural gene is to be transcribed into mRNA and then translated into a polypeptide.
Advanced Usage and Context
- In genetics and molecular biology: The term is used to contrast protein-coding genes with regulatory sequences (like promoters and operators) and genes that code for regulatory RNAs (like tRNA or rRNA genes).
- The operon model distinguishes between structural genes, which produce enzymes, and the operator region, which controls their expression.
- "Structural gene mutation": A mutation occurring within the coding sequence of a structural gene.
- A point mutation in the structural gene for hemoglobin can result in sickle cell anemia.
Variants and Related Words
- Cistron: A term sometimes used synonymously with structural gene, particularly in older literature, referring to a genetic unit that codes for a single polypeptide.
- Coding sequence (CDS): The portion of a gene's DNA or RNA that codes for protein.
- Exon: The segments of a structural gene that are expressed and code for parts of the final protein product.
Synonyms
- Protein-coding gene
- Gene (in the specific context of coding for a protein product)
Related Concepts (Not Phrasal Verbs or Idioms)
- Regulatory gene: A gene involved in controlling the expression of one or more structural genes.
- Operon: A functioning unit of DNA containing a cluster of structural genes under the control of a single promoter.
- Transcription: The process of copying a structural gene's DNA sequence into messenger RNA (mRNA).
Noun
- a gene that controls the production of a specific protein or peptide