Responsible for synthesis of pseudouridine from uracil at positions 955, 2504 and 2580 in 23S ribosomal RNA. uridine(955/2504/2580) in 23S rRNA = pseudouridine(955/2504/2580) in 23S rRNA No visible growth phenotype (PubMed:9660827). An rluC deletion suppresses a bipA deletion; in a double rluC-bipA deletion the cold-sensitive growth and ribosome assembly defects at 20 degrees Celsius due to bipA are fully suppressed and decreased capsule synthesis is partially suppressed (PubMed:18820021, PubMed:25777676). Belongs to the pseudouridine synthase RluA family.