A three-subunit Hap complex that interacts with the RNA polymerase If Elong
ator was isolated fi-om yeast. Deletions of genes for two Hap subunits, HAP
1 and HAP3, confer pGKL killer-insensitive and weak Elongator phenotypes. P
referential interaction of the Hap complex with free rather than RNA polyme
rase II-associated Elongator suggests a role in the regulation of Elongator
activity.