In:
European Journal of Biochemistry, Wiley, Vol. 184, No. 3 ( 1989-10), p. 603-609
Abstract:
Site‐directed mutagenesis was used to change the phosphopantetheine attachment site (Ser38) of spinach acyl carrier protein I (ACP‐I) from a serine to a threonine or cysteine residue. Although the native ACP‐I is fully phosphopantethenylated when expressed in Escherichia coli , the THACP‐I and CY‐ACP‐I mutants were found to be completely devoid of the phosphopantetheine group. Therefore, the E. coli holoACP synthase requires serine for in vivo phosphopantetheine addition to spinach ACP‐I. Spinach holoACP‐synthase was completely inactive in vitro with either the TH‐ACP‐I or CY‐ACP‐I mutants. In addition, TH‐ACP‐I and CY‐ACP‐I were strong inhibitors of spinach holoACP synthase. The mutant ACPs were weak or ineffective as inhibitors of spinach fatty acid synthesis and spinach oleoyl‐ACP hydrolase. Compared to holoACP‐I, the mutant apoACP‐I analogs had: (a) altered mobility in SDS and native gel electrophoresis, (b) altered binding to anti‐(spinach ACP‐I) antibodies and (c) altered isoelectric points. The combined physical, immunological and enzyme inhibition data indicate that attachment of the phosphopantheine prosthetic group alters ACP conformation.
Type of Medium:
Online Resource
ISSN:
0014-2956
,
1432-1033
DOI:
10.1111/ejb.1989.184.issue-3
DOI:
10.1111/j.1432-1033.1989.tb15056.x
Language:
English
Publisher:
Wiley
Publication Date:
1989
detail.hit.zdb_id:
1398347-7
detail.hit.zdb_id:
1464377-7
SSG:
12
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