Importance of the C-terminal helix to the stability and enzymatic activity of Escherichia coli ribonuclease H.


Abstract

The ribonuclease H (RNase H) family of enzymes selectively degrades the RNA strand of RNA-DNA hybrids. This activity is essential for retroviruses such as HIV and resides in a domain of the larger reverse transcriptase molecule. RNase H from Escherichia coli is the best-characterized member of the family and serves as a model for structure/function studies. Despite having almost identical alpha + beta folds, the isolated domain from HIV is inactive and much less stable than the E. coli homolog. The HIV domain also shows increased disorder in its C-terminal regions (E-helix and His-containing loop). We investigated the importance of this region by studying a variant of E. coli RNase H lacking these elements (RNHdeltaE). Despite the elimination of 33 of 155 residues (including a complete helix), this C-terminal deletion mutant folds cooperatively as a subdomain. Surprisingly, this protein lacking residues near the active site retains weak Mn2+-dependent activity. A peptide corresponding to the deleted E-helix is helical in isolation and stimulates the activity of the deletion mutant in vitro. These results have implications for the catalytic mechanism of RNase H and drug design targeted to HIV reverse transcriptase. Study holds ProTherm entries: 2761, 2762 Extra Details: measurement was made in the presence of 0.8M GdnHCl ribonuclease HI; stability; helix; subdomain; HIV;,Escherichia coli; activity

Submission Details

ID: gVxPLfCT

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:19 p.m.

Version: 1

Publication Details
Goedken ER;Raschke TM;Marqusee S,Biochemistry (1997) Importance of the C-terminal helix to the stability and enzymatic activity of Escherichia coli ribonuclease H. PMID:9188727
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
4Z0U 2015-03-26T00:00:00+0000 2.0 RNase HI/SSB-Ct complex
1F21 2000-05-22T00:00:00+0000 1.4 DIVALENT METAL COFACTOR BINDING IN THE KINETIC FOLDING TRAJECTORY OF E. COLI RIBONUCLEASE HI
1G15 2000-10-10T00:00:00+0000 1.9 CO-CRYSTAL OF E. COLI RNASE HI WITH TWO MN2+ IONS BOUND IN THE THE ACTIVE SITE
1GOA 1993-05-10T00:00:00+0000 1.9 COOPERATIVE STABILIZATION OF ESCHERICHIA COLI RIBONUCLEASE HI BY INSERTION OF GLY-80B AND GLY-77-> ALA SUBSTITUTION
1GOB 1993-05-10T00:00:00+0000 2.0 COOPERATIVE STABILIZATION OF ESCHERICHIA COLI RIBONUCLEASE HI BY INSERTION OF GLY-80B AND GLY-77-> ALA SUBSTITUTION
1GOC 1993-05-10T00:00:00+0000 2.0 COOPERATIVE STABILIZATION OF ESCHERICHIA COLI RIBONUCLEASE HI BY INSERTION OF GLY-80B AND GLY-77-> ALA SUBSTITUTION
1JL1 2001-07-13T00:00:00+0000 1.3 D10A E. coli ribonuclease HI
1JL2 2001-07-13T00:00:00+0000 1.76 Crystal structure of TCEO RNase H-a chimera combining the folding core from T. thermophilus RNase H and the remaining region of E. coli RNase H
1JXB 2001-09-06T00:00:00+0000 1.6 I53A, a point mutant of the cysteine-free variant of E. coli Rnase HI
1KVA 1996-10-04T00:00:00+0000 1.8 E. COLI RIBONUCLEASE HI D134A MUTANT

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Ribonuclease HI A7ZHV1 RNH_ECO24
100.0 Ribonuclease HI B7MBJ0 RNH_ECO45
100.0 Ribonuclease HI P0A7Y6 RNH_ECO57
100.0 Ribonuclease HI B5Z0I8 RNH_ECO5E
100.0 Ribonuclease HI B7NKW4 RNH_ECO7I
100.0 Ribonuclease HI B7MQ23 RNH_ECO81
100.0 Ribonuclease HI B7M213 RNH_ECO8A
100.0 Ribonuclease HI C4ZRV1 RNH_ECOBW
100.0 Ribonuclease HI B1XD78 RNH_ECODH
100.0 Ribonuclease HI P0A7Y5 RNH_ECOL6
100.0 Ribonuclease HI B1IPU4 RNH_ECOLC
100.0 Ribonuclease HI P0A7Y4 RNH_ECOLI
100.0 Ribonuclease HI B7N876 RNH_ECOLU
100.0 Ribonuclease HI B6HZS7 RNH_ECOSE
100.0 Ribonuclease HI B1LHM3 RNH_ECOSM
100.0 Ribonuclease HI B7LW89 RNH_ESCF3
100.0 Ribonuclease HI B2U352 RNH_SHIB3
100.0 Ribonuclease HI Q325T2 RNH_SHIBS
100.0 Ribonuclease HI Q32JP9 RNH_SHIDS
100.0 Ribonuclease HI P0A7Y7 RNH_SHIFL
100.0 Ribonuclease HI Q3Z5E9 RNH_SHISS
99.4 Ribonuclease HI B7UJB0 RNH_ECO27
99.4 Ribonuclease HI B7LHC0 RNH_ECO55
99.4 Ribonuclease HI A7ZWF6 RNH_ECOHS
99.4 Ribonuclease HI Q0TLC3 RNH_ECOL5
93.5 Ribonuclease HI A8AKR0 RNH_CITK8
93.5 Ribonuclease HI B5F8X2 RNH_SALA4
93.5 Ribonuclease HI A9MPF1 RNH_SALAR
93.5 Ribonuclease HI Q57SZ6 RNH_SALCH
93.5 Ribonuclease HI B5FJ58 RNH_SALDC
93.5 Ribonuclease HI B5R449 RNH_SALEP
93.5 Ribonuclease HI B5R5L3 RNH_SALG2
93.5 Ribonuclease HI B4TK85 RNH_SALHS
93.5 Ribonuclease HI B4SV39 RNH_SALNS
93.5 Ribonuclease HI Q5PFD8 RNH_SALPA
93.5 Ribonuclease HI A9MZ19 RNH_SALPB
93.5 Ribonuclease HI B5BDW5 RNH_SALPK
93.5 Ribonuclease HI B4TYH0 RNH_SALSV
93.5 Ribonuclease HI P0A2C0 RNH_SALTI
93.5 Ribonuclease HI P0A2B9 RNH_SALTY
92.9 Ribonuclease HI C0Q6N2 RNH_SALPC
90.9 Ribonuclease HI B5Y1G2 RNH_KLEP3
90.9 Ribonuclease HI A6T512 RNH_KLEP7