High impact information on TOA2

• Both the TOA1 and TOA2 genes are essential for growth of yeast [1].
• Recombinant GST-Kap122p formed a complex with recombinant His(6)-Toa1p/Toa2p [2].
• Mutations in the TOA2 subunit of TFIIA that disrupt TBP-TFIIA complex formation in vitro are also synthetically lethal with spt16 [3].
• Mutational analyses of the Toa2 subunit of TFIIA indicate that loss of functional interaction between TFIIA and TAF40 results in conditional growth phenotypes and defects in transcription [4].
• Substitution mutations in the small subunit of TFIIA (Toa2) at residue Y69 or W76 significantly impaired the ability of TFIIA to stimulate TBP-promoter binding in vitro [5].

Biological context of TOA2

• Sequence of a 28.6 kb region of yeast chromosome XI includes the FBA1 and TOA2 genes, an open reading frame (ORF) similar to a translationally controlled tumour protein, one ORF containing motifs also found in plant storage proteins and 13 ORFs with weak or no homology to known proteins [6].

Anatomical context of TOA2

• Like other substrate-Kap complexes, the Toa1p/Toa2p/Kap122p complex isolated from yeast cytosol or reconstituted from recombinant proteins, was dissociated by RanGTP but not RanGDP [2].

Other interactions of TOA2

• Deletion of KAP122 is not lethal, although deletion of TOA1 and TOA2 is [2].
• Together these data suggest that Kap122p is the major Kap for the import of Toa1p-Toa2p into the nucleus [2].

References