version 3 category.php

<?php get_header(); ?>
<div class="art-content-layout">
    <div class="art-content-layout-row">
        <div class="art-layout-cell art-sidebar1">
         <div class="art-layout-bg"></div>
          <?php get_sidebar('default'); ?>
          <div class="cleared"></div>
        </div>
        <div class="art-layout-cell art-content">
            <?php get_sidebar('top'); ?>
            <?php
                if(have_posts()) {

                    /* Display navigation to next/previous pages when applicable */
                    if ( theme_get_option('theme_' . (theme_is_home() ? 'home_' : '') . 'top_posts_navigation' ) ) {
                        theme_page_navigation();
                    }

                    /* Start the Loop */
                    while (have_posts()) {
                        the_post();
                        get_template_part('content', 'category'); //Added the content file here
                    }

                    /* Display navigation to next/previous pages when applicable */
                    if (theme_get_option('theme_bottom_posts_navigation')) {
                         theme_page_navigation();
                    }

                } else {

                     theme_404_content();

                }
            ?>
            <?php get_sidebar('bottom'); ?>
          <div class="cleared"></div>
        </div>
        <div class="art-layout-cell art-sidebar2">
         <div class="art-layout-bg"></div>
          <?php get_sidebar('secondary'); ?>
          <div class="cleared"></div>
        </div>
    </div>
</div>
<div class="cleared"></div>
<?php get_footer(); ?>