THE HUMAN S3A RIBOSOMAL-PROTEIN - SEQUENCE, LOCATION AND CELL-FREE TRANSCRIPTION OF THE FUNCTIONAL GENE

The intron-containing gene encoding human ribosomal protein S3a (hRPS3 a) was isolated by utilizing a PCR-based strategy to detect a gene-spe cific intron which was subsequently used as a probe for cloning of the entire gene. The hRPS3a gene is composed of six exons and five intron s spanning 5013 bp. As described for other hRP-encoding genes, the pro moter lacks a canonical TATA sequence and a defined CAAT box. Primer e xtension experiments, as well as cell-free transcription, revealed tha t a cytosine functions as the major transcription start point in a pol ypyrimidine region, but a guanosine at position -1 was also able to in itiate transcription. Hybridization analysis of chromosomal DNA from a panel of human-rodent somatic cell hybrids revealed that hRPS3a is en coded by a single locus in the human genome, present on chromosome 4.