The structural gene that codes for transacetylase enzyme which can transfer acetyl group to `beta`-galactoside is

Options

A. lac z
B. lac a
C. i-gene
D. lac y

Answer

To determine which structural gene codes for the transacetylase enzyme that transfers an acetyl group to beta-galactoside, we can follow these steps:

### Step 1: Understand the context of the question
The question pertains to the lac operon in E. coli, which is responsible for the metabolism of lactose. The lac operon consists of three structural genes: lacZ, lacY, and lacA.

### Step 2: Identify the structural genes
- **lacZ**: This gene encodes for the enzyme beta-galactosidase, which breaks down lactose into glucose and galactose.
- **lacY**: This gene encodes for lactose permease, which facilitates the transport of lactose into the cell.
- **lacA**: This gene encodes for the enzyme transacetylase, which is responsible for transferring an acetyl group to beta-galactoside.

### Step 3: Focus on the specific function of transacetylase
Transacetylase is involved in the modification of beta-galactoside by adding an acetyl group. This function is specifically attributed to the product of the lacA gene.

### Step 4: Conclude the answer
Based on the functions of the structural genes in the lac operon, the structural gene that codes for the transacetylase enzyme is **lacA**.

### Final Answer:
The structural gene that codes for transacetylase enzyme which can transfer acetyl group to beta-galactoside is **lacA**.

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