A STATISTICAL-ANALYSIS OF SEQUENCE FEATURES WITHIN GENES FROM NEUROSPORA-CRASSA

We analyzed gene sequences from Neurospora crassa deposited in GenBank or EMBL for GC content, codon usage, intron prevalence, intron length, exon length, translation initiation sites, and mRNA splice sites. Protein coding regions were 59% GC, and noncoding regions were 49% GC. Codon usage was biased, primarily due to a strong preference for C in the final position of the codons. Over 80% of N. crassa protein coding genes had introns, which are typically 60 nucleotides long. Exons varied greatly in length, but were typically much longer than introns. The distribution of nucleotides surrounding translation initiation and intron splice sites was clearly nonrandom. We derived a consensus translation initiation site of CAMMATGGCT, a 5'-intron donor site of G^GTAAGTnnYCnYY, an internal branchpoint of WRCTRACMnnnnnnYY, and a 3'-acceptor site of WACAG^. (C) 1994 Academic Press, Inc.