first ubiquitin-like (Ubl) domain located at the N-terminus of coronavirus SARS-CoV non-structural protein 3 (Nsp3) and related proteins; This ubiquitin-like (Ubl) domain (Ubl1) is found at the N-terminus of coronavirus Nsp3, a large multi-functional multi-domain protein which is an essential component of the replication/transcription complex (RTC). The functions of Ubl1 in CoVs are related to single-stranded RNA (ssRNA) binding and to interacting with the nucleocapsid (N) protein. SARS-CoV Ubl1 has been shown to bind ssRNA having AUA patterns, and since the 5'-UTR of the SARS-CoV genome has a number of AUA repeats, it may bind there. In mouse hepatitis virus (MHV), this Ubl1 domain binds the cognate N protein. Adjacent to Ubl1 is a Glu-rich acidic region (also referred to as hypervariable region, HVR); Ubl1 together with HVR has been called Nsp3a. Currently, the function of HVR in CoVs is unknown. This model corresponds to one of two Ubl domains in Nsp3; the other is located N-terminal to the papain-like protease (PLpro) and is not represented by this model.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1063742737  39 IRVRVKYGSVHHEISINSQSTFGELKKILSGATGVHHQDMQIIYKDKERDSKMFLDLSGVKDRSKLILI 107
Cdd:cd17054     2 IKIKVSHGAVYHEVTVSAQATFGDLKKLLVQDTGLQPQEQKLLFRGKEKDDKDFLDLAGVKDKAKVVLV 70

ubiquitin-like (Ubl) domain found in Arabidopsis thaliana Bcl-2-associated athanogenes AtBAG1, AtBAG2, AtBAG3, AtBAG4, and similar proteins; The family includes four Arabidopsis BAG family proteins (AtBAG1, AtBAG2, AtBAG3, AtBAG4) that have very similar domain organizations with a ubiquitin-like (Ubl) domain in the N-terminus and a BAG domain in the C-terminus. They may function as co-chaperones that regulate diverse cellular pathways, such as programmed cell death and stress responses. AtBAG1, AtBAG3, and AtBAG4 are predicted to localize in the cytoplasm, but the localization of AtBAG2 is the microbody. AtBAG4 can interact with Hsc70. The overexpression of AtBAG4 in tobacco plants confers tolerance to a wide range of abiotic stresses such as UV light, cold, oxidants, and salt treatments.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1063742737  39 IRVRVKYGSVHHEISINSQSTFGELKKILSGATGVHHQDMQIIYKDKERDSKMFLDLSGVKDRSKLILI 107
Cdd:cd17054     2 IKIKVSHGAVYHEVTVSAQATFGDLKKLLVQDTGLQPQEQKLLFRGKEKDDKDFLDLAGVKDKAKVVLV 70

ubiquitin-like (Ubl) domain found in Arabidopsis thaliana Bcl-2-associated athanogenes AtBAG1, AtBAG2, AtBAG3, AtBAG4, and similar proteins; The family includes four Arabidopsis BAG family proteins (AtBAG1, AtBAG2, AtBAG3, AtBAG4) that have very similar domain organizations with a ubiquitin-like (Ubl) domain in the N-terminus and a BAG domain in the C-terminus. They may function as co-chaperones that regulate diverse cellular pathways, such as programmed cell death and stress responses. AtBAG1, AtBAG3, and AtBAG4 are predicted to localize in the cytoplasm, but the localization of AtBAG2 is the microbody. AtBAG4 can interact with Hsc70. The overexpression of AtBAG4 in tobacco plants confers tolerance to a wide range of abiotic stresses such as UV light, cold, oxidants, and salt treatments.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 1063742737  39 IRVRVKYGSVHHEISINSQSTFGELKKILSGATGVHHQDMQIIYKDKERDSKMFLDLSGVKDRSKLILI 107
Cdd:cd17054     2 IKIKVSHGAVYHEVTVSAQATFGDLKKLLVQDTGLQPQEQKLLFRGKEKDDKDFLDLAGVKDKAKVVLV 70

ubiquitin-like (Ubl) domain found in ubiquitin and ubiquitin-like Ubl proteins; Ubiquitin-like (Ubl) proteins have a similar ubiquitin (Ub) beta-grasp fold and attach to other proteins in a Ubl manner but with biochemically distinct roles. Ub and Ubl proteins conjugate and deconjugate via ligases and peptidases to covalently modify target polypeptides. Some Ubl domains have adaptor roles in Ub-signaling by mediating protein-protein interaction. Prokaryotic sulfur carrier proteins are Ub-related proteins that can be activated in an ATP-dependent manner. Polyubiquitination signals for a diverse set of cellular events via different isopeptide linkages formed between the C terminus of one ubiquitin (Ub) and the epsilon-amine of K6, K11, K27, K29, K33, K48, or K63 of a second Ub. One of these seven lysine residues (K27, Ub numbering) is conserved in this Ubl_ubiquitin_like family. K27-linked Ub chains are versatile and can be recognized by several downstream receptor proteins. K27 has roles beyond chain linkage, such as in Ubl NEDD8 (which contains many of the same lysines (K6, K11, K27, K33, K48) as Ub) where K27 has a role (other than conjugation) in the mechanism of protein neddylation.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 1063742737  41 VRVKYGSVH-HEISINSQSTFGELKKILSGATGVHHQDMQIIYKDKERDSKMFLDLSGVKDRSKLILI 107
Cdd:cd17039     1 ITVKTLDGKtYTVEVDPDDTVADLKEKIEEKTGIPVEQQRLIYNGKELKDDKTLSDYGIKDGSTIHLV 68