Definition

1. 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

1. a gene that controls the production of a specific protein or peptide