Disease relevance of RPA135

• However, the A135-AC40 interaction is weak compared with the E. coli alpha-beta interaction, and A135 mutation that abolishes the interaction is phenotypically silent [1].

High impact information on RPA135

• Furthermore, measurements of the exchange of A135 and A190 subunits between preexistent Pol I and newly synthesized Pol I showed that these two largest subunits of Pol I do not disassociate through many rounds of transcription in vivo [2].
• Finally, a strain was constructed in which transcription of the SRP3 gene was controlled by the inducible GAL7 promoter [3].
• Second, the deduced amino acid sequence contains known amino acid sequences of two tryptic peptides from the A135 subunit of RNA polymerase I purified from S. cerevisiae [3].
• We have cloned the SRP3 gene by using its suppressor activity and determined its complete nucleotide sequence [3].
• When this strain, which can grow on galactose but not on glucose, was shifted from galactose medium to glucose medium, a large decrease in the cellular concentration of A135 was observed by Western blot analysis [3].

Biological context of RPA135

• In frame TGA codons were detected, which are likely to encode conserved cysteinyl residues in the putative zinc-finger region of the RPA2 gene [4].
• No other amino acid at position 135 gave either the wild type phenotype or the normal enzyme activity of A135 [5].
• The importance of the A135 residue was probed genetically by analysis involving both site-directed mutagenesis and randomly generated second-site intragenic suppressor mutations [5].

Associations of RPA135 with chemical compounds

• Curiously, the essential function of the Rpa135 Zn-binding domain is not related to Zn(2+) binding per se, since replacement of only one of the four cysteine residues with alanine led to the loss of Rpa135 function [6].

Other interactions of RPA135

• Based on these correlations, the minimal subunit composition of S. cerevisiae (and Saccharomyces carlsbergensis) RNA polymerase A was tentatively defined as A190, A135, A40, A27, A23, A19, and A14 [7].
• Gel-filtration studies revealed an accumulation of the smaller Rpc19p-containing complex, but not of A135, in the gtr1Delta strain [8].
• They were also found in other positions in both the RPA2 and RPB2 genes [4].
• We also demonstrate that determinants of RNAP assembly are conserved, and that a homologue of beta Asp(1084) in A135, the beta-like subunit of yeast RNAP I, is responsible for interaction with AC40, the largest alpha-like subunit [1].

Analytical, diagnostic and therapeutic context of RPA135

• Separation of the protein subunit components by 5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analysis by autoradiography and silver staining revealed that the two largest subunits (A190 and A135) were radiolabeled [9].

References