Aspergillus nidulans MATE mobile elements: evidence of RIPping?

Clutterbuck., John


MATE elements were identified as a result of investigations into the AMA1 sequence which allows autonomous replication of plasmids in A. nidulans (Aleksenko & Clutterbuck 1996 Mol. Microbiol. 19: 565-574). Five MATE elements can be identified in the Glasgow strains of A. nidulans, while wild isolates contain variable numbers, inserted at different sites. MATE sequences obtained from the Cereon Microbial Sequence Database show elements of 6097 bp, flanked by 9 bp target site repeats. The most notable sequence features are numerous Spe motifs, [(RWCTAGWYNNN)2-4], scattered throughout, and potential stem-loop structures at each end of the elements. No ORFs with significant homology have been identified, and the mechanism of transposition and relationship to plasmid replication are both unknown. MATE1a and MATE1b are inserted back-to-back on chromosome IV, separated by 374 bp of unique sequence. Partial sequencing indicates that these two copies are identical, but solitary elements on other chromosomes differ from MATE1 by numerous transition mutations. Comparisons between these solo copies indicate greater divergence, suggesting independent origins from MATE1 or its precursor. The mutated copies show both T-C and G-A substitutions in patterns suggesting independent mutation of each strand. The doublet preference for mutation is CpG > CpA, with other doublets rarely mutated. It is suggested that mutation may have occurred by a RIP-like mechanism, from which MATE1 elements are protected by their putatively telomeric chromosomal location

abstract No: 

Fungal Genet. Newsl. 50 (Supl):abstract

Full conference title: 

22nd Fungal Genetics Conference
    • Fungal Genetics Conference 22nd (2001)