International Journal on Recent and Innovation Trends in Computing and Communication ISSN: 2321-8169 Volume: 5 Issue: 7 111 – 115 _______________________________________________________________________________________________ 111 IJRITCC | July 2017, Available @ http://www.ijritcc.org _______________________________________________________________________________________ In Silico Molecular Insights on the Structure-Function Aspects of ACC Deaminase of a Non-Pathogenic Klebsiella Pneumoniae Krishnendu Pramanik 1 , Pallab Kumar Ghosh 2 , Tushar Kanti Maiti 1 * 1 Microbiology Laboratory, UGC Centre for Advanced Study, Department of Botany, Burdwan University, Burdwan-713104, West Bengal, India 2 Department of Marine Science, Calcutta University, Ballygunge Science College, 35 B.C Road, Kolkata-700019, West Bengal, India *Corresponding author: email: tkmbu@yahoo.co.in Abstract—Bacterial 1-aminocyclopropane-1-carboxylic acid deaminase (ACCD) is known to involve in breaking down the 1- aminocyclopropane-1-carboxylic acid (ACC), immediate precursor of ethylene, into a-ketobutyrate and ammonia. This is required when stress (biotic or abiotic) induced ethylene content is accelerated in plant cells resulting in reduction in plant biomass and yield. Klebsiellapneumoniae, although previously considered only as a pathogenic bacteria, there are some strains reported till date to prove it as a plant growth promoting bacteria (PGPB). ACCD activity has reported from the said strain but the present study is emphasized on its molecular proteomic structures and functions studied in silico. The present work revealed that the ACCD of K. pneumoniae is a 36.5 kDatetrameric stable protein found in intracellular condition. The phylogenetic analysis clearly depicts its similarity with several other ACCD reported from different bacterial genera. The structure-function insight would definitely help future researchers in designing wet lab as well as dry lab experiments. Keywords-Klebsiella pneumoniae; non-pathogenic; PGPR, in silico; protein modeling. __________________________________________________*****_________________________________________________ I. INTRODUCTION ACC deaminase(EC3.5.99.7)is a microbial hydrolase family enzyme found both in fungi and bacteria [1]. On the other hand, ACC is the precursor of plant hormone ethylene found in plant cells, isolated from Pseudomonas sp. strain ACP [2]. Ethylene is a plant hormone essential for plant growth, fruit ripening; however excess ethylene has deleterious effect of root and soot development. The ACC deaminase producing rhizobacteria split the ACC into alpha ketobutyrate and ammonia using as carbon or nitrogen source, eventually reduce the level of ACC and ethylene [3]. Thus rhizobacteria are bound to root or seed and act as a sink for ACC and reduced the levels of ethylene. So ACC deaminase producing PGPR promote plant growth particularly under stress conditions by the regulation of accelerated ethylene production in response to various stress. Thus ACC deaminase enzyme or protein (ACCD) has importance in agriculture particularly in stress condition. There are very few report of the in silico characterization of this protein found in rhizobacteria [4]. The present study describes in silico analysis of molecular proteomic structure of the ACCD protein isolated from Klebsiellapneumoniae. Attempts were also made the computational analysis of this protein to know the structural and functional insight essential for both dry and wet laboratory experiments. II. MATERIAL AND METHODS a. Retrieval and selection of reference sequence Protein and corresponding gene sequence of Klebsiellapneumoniae was retrieved from NCBI (http://www.ncbi.nlm.nih.gov/) database in FASTA format. This sequence was used for further computational investigation including the molecular modeling. b. Construction of phylogenetic tree of similar sequences BLAST search was performed by using NCBI-BLAST to find the similar protein sequences with selected protein and phylogenetic tree was constructed using MEGA7 [5] software to find the evolutionary distances among the proteins. Whole genome sequences were omitted and partial sequences were selected from the search result. c. Primary sequence analysis Primary sequence analysis included the physicochemical characteristics of the K. pneumoniae protein (AEQ29825.1). ExpasyProtParam tool [6] was used to determine the molecular weight and amino acid composition. d. Secondary structure prediction Prediction of secondary structure (which involved the estimation of number of helices, sheets, turns, and coils in the amino acid sequence) was done from CFSSP: Chou and