Chromosome XIII – A brief description

The organization and features of chromosome XIII is very consistent with the others observed in S. cerevisiae. Generally, genes appear to be evenly distributed through the genome, having no preference for a DNA strand, and having lower density in the telomeric region. Chromosome XIII has a length of 924430 bp, which correspond to a total of 607 genes. There are 268030 bp in one arm and 656280 bp, in the other. Among the genome of this chromosome, there are 27 genes corresponding to ARS (autonomously replicating sequence), which promote high rate of transformation and extrachromosomal maintenance of plasmid DNA ⁽²⁾. Analysis has shown that they function as origins of DNA duplication ⁽²⁾. One of the nucleotide sequences of an ARS gene is shown below, in image 1. In addition to the ARS genes, there are genes throughout the chromosome in charge of its replication, among them are GIM5/ YML094W, which is responsible for the biogenesis of microtubules; SPG5/YMR191W, required for proteasome assembly, and SPG4/YMR107 both required for high temperature survival, and both genes responsible for the stationary phase. Also, SGS1/YMR190C, in charge of maintaining genome’s integrity and MSS11/YMR164C, a transcription factor, involved in regulation of invasive growth and starch degradation. These are only a few examples of the many genes capable of replicating chromosome XIII.

GTTGTCATTGAGTGAAATCAATTGAAAGTATGTACATTTGGAAGAGCATATGTTAAATATTTTATTTATAGATTTTTCGTTGTGAAATATTATTTTTTTTTTTTTGAAAAAAATGTCGGACTTTATTCCTCCTAATTATTAATAAAATACGAATATATATCTAAATATAATTAATGCTTATTTACATGAAAAATCATCAATCGTAAACAGTTGATTAAAAAACAAAAACTTTATCGGTTCCATTACC

Image 1: Nucleotide sequences of an ARS gene (chrXIII chrXIII:94217..94463 class=ARS length=247 bp )

⁽¹⁾ S. Bowman, C. Churcher, K. Badcock, D. Brown, T. Chillingworth, et al; The nucleotide sequence of Saccharomyces cerevisiae chromosome XIII; The Sanger Centre, Welcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK

⁽²⁾  Clyne RK, Kelly TJ; Identification of autonomously replicating sequence (ARS) elements in eukaryotic cells; Page 1; 1997 Nov 13

Grupo 4.3

Licenciatura bioquimica Uminho

Adriano Silva

Inês Ferreira

Thais Silva

Francisco Magalhães