Component of a CST-like subcomplex of the holoenzyme telomerase ribonucleoprotein complex, which stimulates telomerase complementary-strand synthesis (PubMed:26551074). Telomerase is an essential ribonucleoprotein enzyme that copies new telomeric repeats onto chromosome ends by repetitively synthesizing the short telomere-repeat sequence 5'-TTGGGG-3' using an RNA template component TER (PubMed:26551074). The CST-like subcomplex (also named 7-4-1) binds telomeric single-stranded DNA and coordinates telomere G-strand and C-strand synthesis (PubMed:26551074). Component of the telomerase holoenzyme complex, composed of the catalytic core (the catalytic subunit TERT, the telomerase RNA template component TER and TAP65/p65), which is associated with two heterotrimeric subcomplexes: (i) the replication protein A (RPA)-related subcomplex, composed of TEB1, RPA2/TEB2 and RPA3/TEB3 and (ii) the CST-like subcomplex, composed of TAP75/p75, TAP45/p45 and TAP19/p19 (PubMed:19941821, PubMed:23552895, PubMed:26551074, PubMed:26472759). TEB1 and the CST-like subcomplex are tethered to the catalytic core by TAP50/p50 (PubMed:19941821, PubMed:23552895, PubMed:26472759). Critically short telomeres.