Structural gene
Encyclopedia
A structural gene is a gene
that codes for any RNA or protein product other than a regulatory factor (i.e. regulatory protein). It may code for a structural protein, an enzyme
, or an RNA molecule not involved in regulation. Structural genes represent an enormous variety of protein structures and functions, including structural proteins, enzymes with catalytic activities and so on.
These genes are needed for the morphological or functional traits of the cell. In Eukaryotes, these occur in spilt-form, segmented into introns and exons. But Prokaryotes, these are continuous. The structural genes are concerned with the synthesis of polypeptide chain or a number of polypeptide chains and are also concerned with the synthesis of different types of RNA required during protein synthesis.
In the Lac-Operon concept, these genes are associated with the synthesis of those enzymes that are needed for the catabolism of Lactose. In lac-operon, there are three structural genes:
a, Lac Z gene for beta-galactosodase enzyme.
b, Lac Y gene for galactose permease enzyme.
c, Lac A gene for thio galactoside trans acetylase enzyme.
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
that codes for any RNA or protein product other than a regulatory factor (i.e. regulatory protein). It may code for a structural protein, an enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
, or an RNA molecule not involved in regulation. Structural genes represent an enormous variety of protein structures and functions, including structural proteins, enzymes with catalytic activities and so on.
These genes are needed for the morphological or functional traits of the cell. In Eukaryotes, these occur in spilt-form, segmented into introns and exons. But Prokaryotes, these are continuous. The structural genes are concerned with the synthesis of polypeptide chain or a number of polypeptide chains and are also concerned with the synthesis of different types of RNA required during protein synthesis.
In the Lac-Operon concept, these genes are associated with the synthesis of those enzymes that are needed for the catabolism of Lactose. In lac-operon, there are three structural genes:
a, Lac Z gene for beta-galactosodase enzyme.
b, Lac Y gene for galactose permease enzyme.
c, Lac A gene for thio galactoside trans acetylase enzyme.