Pati U K
Department of Medicine, Medical College of Georgia, Augusta 30912-3100.
Gene. 1994 Aug 5;145(2):289-92. doi: 10.1016/0378-1119(94)90022-1.
The cDNA cloning of the human polII 14-kDa subunit, hRPB14, and the comparison of its aa sequence with those of other pol subunits are described. The aa sequence of hRPB14 has homology to yeast poIII subunit RPB11 (44%), to a common subunit of yeast polI and polIII AC19 (24%) and to a Caenorhabditis elegans sequence (33%). hRPB14 contains a 19-aa motif, located in its N terminus, which was also found in human polII 33-kDa subunit hRPB33, yeast pol subunits (AC40, AC19, RPB3 and RPB11), and in the bacterial pol alpha subunit, which was involved in subunit assembly. This motif was also conserved in the conjugation-specific gene products of Tetrahymena (CnjC), Merchantia polymorpha chloroplast DNA (RNLVA) and C. elegans DNA (CEF58A4; deduced from the nucleotide sequence and of unknown function). The evolutionary emergence of a probable eukaryotic heterodimer, hRPB14/hRPB33, from a prokaryotic homodimer, alpha 2, is hypothesized.
本文描述了人类聚合酶II 14-kDa亚基hRPB14的cDNA克隆，以及其氨基酸序列与其他聚合酶亚基氨基酸序列的比较。hRPB14的氨基酸序列与酵母聚合酶III亚基RPB11具有同源性（44%），与酵母聚合酶I和聚合酶III的共同亚基AC19具有同源性（24%），与秀丽隐杆线虫的一个序列具有同源性（33%）。hRPB14在其N端含有一个19个氨基酸的基序，该基序也存在于人类聚合酶II 33-kDa亚基hRPB33、酵母聚合酶亚基（AC40、AC19、RPB3和RPB11）以及细菌聚合酶α亚基中，它参与亚基组装。这个基序在嗜热四膜虫的接合特异性基因产物（CnjC）、多形梅氏藻叶绿体DNA（RNLVA）和秀丽隐杆线虫DNA（CEF58A4；从核苷酸序列推导而来，功能未知）中也保守。推测真核异二聚体hRPB14/hRPB33可能是从原核同二聚体α2进化而来。
