Elongator complex-associated factor that is not a structural subunit but rather transiently contacts the complex (PubMed:25518926). Regulates both meristem activity and organ growth; acts as a positive regulator of adaxial leaf patterning by modulating both cell division and differentiation (PubMed:12615938, PubMed:8392411, PubMed:11589569, PubMed:15894610, PubMed:25518926). Required for an early step in synthesis of 5-carbamoylmethyl (ncm5) groups present on uridines (ncm5U) at the wobble position in tRNA (PubMed:20836892). Interacts with the elongator complex (By similarity). Binds to calmodulin in a calcium-dependent manner (PubMed:12615938). Expressed in roots, hypocotyls, cotyledons, shoot apices, stems, inflorescence apices, leaves and flowers. Detected in globular-, heart-, and torpedo-stage embryos, in the outer integuments of ovules and in the funiculi. Also expressed in the peripheral zone of the shoot apical meristem (SAM) corresponding to the central zone. In elongating tissues, restricted at the periphery of the vascular bundle. In shoot and inflorescence apices, mostly present in the L2 layer, and, at lower levels, in the L1 layer, but absent of the L3 layer. In young leaf primordia, localized in the basal part of the dorsal side. In older leaf primordia, detected in vascular bundles and in the mesophyll between the vascular bundles. In expanding leaves, confined to stomatal guard cells, and individual palisade and spongy mesophyll parenchyma cells. In general, present around the vascular bundles. Expressed in young flower organs but not in mature sepals and petals. Gradient accumulation in the stamens and carpels, with the highest activity at the tip of the organs. Present in the meristematic and elongation zones of the primary root and in the vascular bundle of the differentiation zone. Defective organ formation due to disorganized shoot, inflorescence, flower, and root meristems leading to stunted roots, few root hairs, lanceolate leaves, and a highly enlarged, disorganized shoot apex that does not produce an inflorescence (PubMed:12615938, PubMed:8392411, PubMed:10353913, PubMed:11589569, PubMed:15894610, PubMed:25518926). Altered cell division and cell differentiation in leaves (PubMed:25518926). No detectable 5-carbamoylmethyluridine (ncm5U) modified nucleosides (PubMed:20836892). Belongs to the KTI12 family.