SUMMARY PARAGRAPH for BTT1
BTT1 encodes the beta3 subunit of the nascent polypeptide-associated complex (NAC) (alpha, beta1, beta3). The alpha and beta1 subunits are encoded by EGD2 and EGD1, respectively. This complex binds to ribosomes via the beta-subunits in a salt-sensitive manner, in close proximity to nascent polypeptides (2). Loss of BTT1 has little effect, but cells lacking both Btt1p and Egd1p, which are similar in sequence and are both homologs of human BTF3L3, display several phenotypes (1). These include inability to grow at 37C (2), increased expression of GAL1 and GAL10, and also elevated expression of ACT1 and SSO1 (1). The lack of a drastic phenotype at optimal conditions of cells missing subunits of the NAC, coupled with inferred variability in complex composition, suggests either the existence of a substitute for the NAC or that cells tolerate the absence of the NAC (2).
Last updated: 2004-11-05