Nucleic acid and protein sequences of phosphocholine-binding light chains

Area of Science:

• Immunology
• Molecular Biology
• Genetics

Background:

• Immunoglobulin light chains are crucial components of the adaptive immune system.
• The S107 mouse immunoglobulin light chain is a well-characterized example used in immunological studies.
• Understanding the genetic basis of immunoglobulin diversity is fundamental to immunology.

Purpose of the Study:

• To clone and determine the complete nucleotide sequence of the S107 mouse immunoglobulin kappa light chain gene.
• To analyze the encoded amino acid sequence and compare it with known protein sequences.
• To identify the specific joining (J) gene segment involved in the rearrangement of the kappa light chain locus.

Main Methods:

• Cloning of an 18-kilobase DNA fragment from total cellular DNA.
• Determination of the complete nucleotide sequence of the kappa-chain variable-region gene.
• Direct sequence analysis to confirm the J gene segment usage.

Main Results:

• The complete nucleotide sequence of the S107 mouse kappa light chain variable-region gene was determined.
• The deduced amino acid sequence matched the T15 light chain protein sequence up to residue 88.
• Sequence analysis confirmed the utilization of the J1 joining segment in the active gene.

Conclusions:

• The study provides the complete nucleotide sequence of the S107 mouse immunoglobulin kappa light chain gene.
• The findings confirm the structural similarity between the S107 and T15 light chains at the protein level.
• The J1 joining segment is essential for generating the functional S107 kappa light chain.