Further analysis of the CAP59 locus of Cryptococcus neoformans: structure defined by forced expression and description of a new ribosomal protein-encoding gene.
Cryptococcus neoformans (Cn) produces an extracellular polysaccharide capsule that is an essential factor for virulence. We previously isolated a gene, CAP59, which is necessary for capsule formation. To dissect the functional region of CAP59, we placed it under control of the Cn GAL7 promoter (pGAL7). Among the several pGAL7::CAP59 fusion constructs, only the one containing the entire open reading frame of CAP59 was able to complement the acapsular phenotype under galactose induction. A missense mutation in the coding region abolished complementation by the fusion construct. We also found that the CAP59 locus is contiguous to a convergently transcribed L27 ribosomal protein-encoding gene (CL27). The distance between the cDNA ends of these two genes is only 25 bp. CL27 has two introns near its N terminus. The translated CL27 protein is 183 amino acids (aa) in length with an estimated molecular mass of 20 kDa, and the first 34 aa at the N terminus may be a targeting peptide for mitochondria. A high degree of restriction-fragment-length polymorphism was detected in the DNA sequence containing CAP59 and CL27.
Chang
Y C
YC
Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
Wickes
B L
BL
Kwon-Chung
K J
KJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D003455:Cryptococcus neoformans / Q000235:genetics* / Q000472:pathogenicity; D004271:DNA, Fungal / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D012150:Polymorphism, Restriction Fragment Length; D012333:RNA, Messenger / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics*; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
C087781:CAP59 protein, Cryptococcus neoformans; D004271:DNA, Fungal; D005656:Fungal Proteins; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C034661:ribosomal proteins L27