PMID- 31376470
OWN - NLM
STAT- MEDLINE
DCOM- 20200608
LR  - 20200608
IS  - 1095-8657 (Electronic)
IS  - 1047-8477 (Linking)
VI  - 208
IP  - 1
DP  - 2019 Oct 1
TI  - The structural basis of the low catalytic activities of the two minor beta-carbonic 
      anhydrases of the filamentous fungus Aspergillus fumigatus.
PG  - 61-68
LID - S1047-8477(19)30159-5 [pii]
LID - 10.1016/j.jsb.2019.07.011 [doi]
AB  - The beta-carbonic anhydrases (beta-CAs) are widely distributed zinc-metalloenzymes that 
      play essential roles in growth, survival, development and virulence in fungi. The 
      majority of filamentous ascomycetes possess multiple beta-CA isoforms among which 
      major and minor forms have been characterized. We examined the catalytic behavior 
      of the two minor beta-CAs, CafC and CafD, of Aspergillus fumigatus, and found that 
      both enzymes exhibited low CO(2) hydration activities. To understand the 
      structural basis of their low activities, we performed X-ray crystallographic and 
      site-directed mutagenesis studies. Both enzymes exist as homodimers. Like other 
      Type-I beta-CAs, the CafC active site has an "open" conformation in which the zinc 
      ion is tetrahedrally coordinated by three residues (C36, H88 and C91) and a water 
      molecule. However, L25 and L78 on the rim of the catalytic entry site protrude 
      into the active site cleft, partially occluding access to it. Single (L25G or 
      L78G) and double mutants provided evidence that widening the entrance to the 
      active site greatly accelerates catalytic activity. By contrast, CafD has a 
      typical Type-II "closed" conformation in which the zinc-bound water molecule is 
      replaced by aspartic acid (D36). The most likely explanation for this result is 
      that an arginine that is largely conserved within the beta-CA family is replaced by 
      glycine (G38), so that D36 cannot undergo a conformational change by forming a 
      D-R pair that creates the space for a zinc-bound water molecule and switches the 
      enzyme to the active form. The CafD structure also reveals the presence of a 
      "non-catalytic" zinc ion in the dimer interface, which may contribute to 
      stabilizing the dimeric assembly.
CI  - Copyright (c) 2019 The Author(s). Published by Elsevier Inc. All rights reserved.
FAU - Kim, Songwon
AU  - Kim S
AD  - School of Life Sciences, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, 
      Republic of Korea.
FAU - Kim, Na Jin
AU  - Kim NJ
AD  - School of Life Sciences, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, 
      Republic of Korea.
FAU - Hong, Semi
AU  - Hong S
AD  - School of Life Sciences, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, 
      Republic of Korea.
FAU - Kim, Subin
AU  - Kim S
AD  - School of Life Sciences, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, 
      Republic of Korea.
FAU - Sung, Jongmin
AU  - Sung J
AD  - School of Life Sciences, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, 
      Republic of Korea.
FAU - Jin, Mi Sun
AU  - Jin MS
AD  - School of Life Sciences, GIST, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, 
      Republic of Korea. Electronic address: misunjin@gist.ac.kr.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20190731
PL  - United States
TA  - J Struct Biol
JT  - Journal of structural biology
JID - 9011206
RN  - 0 (Fungal Proteins)
RN  - EC 4.2.1.1 (Carbonic Anhydrases)
RN  - J41CSQ7QDS (Zinc)
SB  - IM
MH  - Aspergillus fumigatus/*metabolism
MH  - Carbonic Anhydrases/*chemistry/*metabolism
MH  - Catalysis
MH  - Catalytic Domain
MH  - Fungal Proteins/*chemistry/*metabolism
MH  - Protein Binding
MH  - Zinc/metabolism
OTO - NOTNLM
OT  - Aspergillus fumigatus
OT  - CafC
OT  - CafD
OT  - Low catalytic activity
OT  - beta-class carbonic anhydrase
EDAT- 2019/08/04 06:00
MHDA- 2020/06/09 06:00
CRDT- 2019/08/04 06:00
PHST- 2019/06/15 00:00 [received]
PHST- 2019/07/29 00:00 [revised]
PHST- 2019/07/30 00:00 [accepted]
PHST- 2019/08/04 06:00 [pubmed]
PHST- 2020/06/09 06:00 [medline]
PHST- 2019/08/04 06:00 [entrez]
AID - S1047-8477(19)30159-5 [pii]
AID - 10.1016/j.jsb.2019.07.011 [doi]
PST - ppublish
SO  - J Struct Biol. 2019 Oct 1;208(1):61-68. doi: 10.1016/j.jsb.2019.07.011. Epub 2019 
      Jul 31.